Inconclusive results using eig in subspace iteration

I am trying to use "eig" command in a subspace iteration code, in which matrices A and B will be updated in each iteration in order to find the first smallest eigen values of a big problem (basically, the subspace runs through specific matrices derived from original big scale matrices). My problem is that when I use the command "eig" the code will not converge to the right solution, however, using another code for calculating eigen pairs, I am able to reach to the right result! So, I want to make sure I am not making any mistakes using "eig" in this matter.The following is my subspace iteration code:

while ecol > 10e-3 && max_Abs_error_norm > 10e-12
    m_n=m_n+1;
    B_mod = B*X_bar;
    X_bar = A\B_mod;
    A_R = X_bar'*A*X_bar;
    B_R = X_bar'*B*X_bar;
    [phi,val]=eig(A_R,B_R);
    [val,phi,sweep]=eigenpair_generalized(A_R,B_R);
    % sort
    [val,ind] = sort(diag(val));
    phi = phi(:, ind);

    X = X_bar*phi;
    for i=1:(L)
         Abs_error_norm(i) = norm(A*X(:,i)-val(i)*B*X(:,i));
    end
    max_Abs_error_norm = max(Abs_error_norm);
    
    X_bar = X;
    if m_n~=1
        for i=1:L
        ecol_1(i) = norm(val(i) - val_store(i));
        ecol = norm(ecol_1);
        end
        val_store = val;
    else
    end
val_store = val;
end

For example the following A_R and B_R are the starting matrices in the line 5 and 6 of the code:

A_R:

3.76356212339912e-07	-2.09083477345828e-08	6.09796273121035e-08	1.16125096563533e-10	8.54792315774798e-10	-1.78957565354304e-10	3.64588901245169e-07	-2.12575801834609e-08	2.95778384545593e-08	1.04548852037412e-10	7.54337443978326e-10	1.47918428730144e-10	3.58166253583762e-07	-1.50411486294677e-08	2.27508077139848e-09	5.08998266385549e-11	7.35592497477014e-10	1.64378433262496e-10	3.54560674790984e-07	-1.31215746002643e-08
-2.09083477342730e-08	6.72245957087280e-07	-2.18639634962637e-08	-1.71926525612297e-09	-1.27383673022489e-10	-7.11372187762411e-10	-1.88899100170015e-08	6.31741631656896e-07	-2.12006678567957e-08	-1.63021194866289e-09	-1.09372872303371e-10	-1.23421660245203e-09	-1.49898389986645e-08	5.83558489864854e-07	-2.21565565712593e-08	-1.46036349767698e-09	-6.55275941132095e-11	-1.30683725608677e-09	-1.10191105552099e-08	5.40004460879015e-07
6.09796273121098e-08	-2.18639634961972e-08	4.71171643216891e-08	1.04797054454652e-10	1.86095906819136e-10	8.01260288650236e-12	6.06016240826248e-08	-2.11963598721298e-08	4.00551836787072e-08	8.36220534690659e-11	1.70245409704536e-10	2.25668528665953e-11	6.02164452093673e-08	-2.04605143113643e-08	3.43646163430180e-08	6.78878595546358e-11	1.56927587198837e-10	1.50923000171879e-11	5.99424102846985e-08	-2.03680063346499e-08
1.16125096563414e-10	-1.71926525612101e-09	1.04797054454702e-10	1.52863228782801e-09	7.61730319665823e-11	2.90892666982479e-12	7.98277666688785e-11	-1.55127298735140e-09	5.46305600339577e-11	7.79819357940273e-10	6.11649135937128e-11	5.00382604780811e-12	5.54540465282430e-11	-1.37209673833278e-09	6.33565161940306e-11	4.34701276279994e-10	2.75780794356816e-11	4.42260486804309e-12	3.69431658456605e-11	-1.24087539226780e-09
8.54792315774812e-10	-1.27383673022310e-10	1.86095906819186e-10	7.61730319665799e-11	5.41326468653499e-10	-6.90952287312927e-13	7.82924904359684e-10	-1.19603500840236e-10	4.30335020913748e-11	6.48006877696352e-11	-1.30723786035514e-10	1.08160932502498e-12	7.47280621190149e-10	-7.09653697897241e-11	4.30795196092820e-12	2.79904115196465e-11	3.93472545836092e-11	1.47324908741991e-12	7.33942614057930e-10	-2.71725494428705e-11
-1.78957565354260e-10	-7.11372187763432e-10	8.01260288654824e-12	2.90892666982850e-12	-6.90952287312627e-13	1.92721989506897e-10	-3.63546650140569e-10	3.74107762169332e-09	1.46997960535703e-12	-6.24910441187741e-11	-3.69513695294017e-12	4.12819006950702e-11	-2.93839904430602e-10	3.65221524784282e-09	-1.44420664706842e-11	-5.52483429664814e-11	-3.37784740323818e-12	-3.64319630028251e-11	-1.19667813242863e-10	1.78034756805592e-09
3.64588901245383e-07	-1.88899100173116e-08	6.06016240826821e-08	7.98277666689620e-11	7.82924904360137e-10	-3.63546650140585e-10	3.68457091745830e-07	-2.66935246645527e-08	3.01059891783646e-08	1.99885274915102e-10	7.67339896837451e-10	-2.81002492354834e-13	3.60658741504259e-07	-2.17263381445007e-08	2.42466362641430e-09	1.59025755093987e-10	7.49949375418138e-10	2.24074497973733e-10	3.56302082753645e-07	-1.62123724739677e-08
-2.12575801833362e-08	6.31741631655756e-07	-2.11963598721385e-08	-1.55127298735091e-09	-1.19603500840958e-10	3.74107762169481e-09	-2.66935246644314e-08	7.60571341160095e-07	-2.14588169242276e-08	-3.86341835071549e-09	-2.30122027434400e-10	1.49679463458960e-09	-2.27314217189395e-08	7.35340682198992e-07	-2.33641804935095e-08	-3.71231499081196e-09	-1.95793125778234e-10	-2.35950158696086e-09	-1.27171200877616e-08	6.23793130032960e-07
2.95778384546184e-08	-2.12006678566718e-08	4.00551836787374e-08	5.46305600338521e-11	4.30335020914587e-11	1.46997960531807e-12	3.01059891783790e-08	-2.14588169241900e-08	3.81776796219074e-08	5.18761021398917e-11	7.78938391626599e-11	-1.48784260116095e-11	3.07221849868984e-08	-2.21488913895600e-08	3.46435071832503e-08	5.42872965395875e-11	9.78734212714599e-11	-2.34743082420234e-11	3.08820328445443e-08	-2.30743445571125e-08
1.04548852037193e-10	-1.63021194866473e-09	8.36220534690290e-11	7.79819357940281e-10	6.48006877696373e-11	-6.24910441187760e-11	1.99885274914897e-10	-3.86341835071973e-09	5.18761021399497e-11	2.88177278801690e-09	1.73527560308934e-10	-2.95791573566135e-11	1.63606363716668e-10	-3.68578964581812e-09	6.70215594167807e-11	1.22058356343448e-09	8.92850271129233e-11	3.15485751136804e-11	2.84994769414440e-11	-2.11221283724199e-09
7.54337443978436e-10	-1.09372872303155e-10	1.70245409704461e-10	6.11649135937103e-11	-1.30723786035513e-10	-3.69513695294040e-12	7.67339896837094e-10	-2.30122027433637e-10	7.78938391624351e-11	1.73527560308932e-10	3.46432736834289e-10	-1.12406376222186e-12	7.50317584899563e-10	-1.87522593302975e-10	-1.80471539474028e-11	8.88175404651439e-11	-7.93438089784584e-11	2.87711136829571e-12	7.27773344056736e-10	-6.42461727021362e-11
1.47918428730006e-10	-1.23421660245135e-09	2.25668528666373e-11	5.00382604780913e-12	1.08160932502493e-12	4.12819006950679e-11	-2.81002492560337e-13	1.49679463458976e-09	-1.48784260115529e-11	-2.95791573566149e-11	-1.12406376222197e-12	1.09083345682025e-10	-9.64214208670492e-11	3.24114993582077e-09	-4.18518424101429e-11	-4.65083941209266e-11	-2.50797392263328e-12	-3.00226119639900e-12	1.83091308587572e-13	2.15157500137760e-09
3.58166253583768e-07	-1.49898389985222e-08	6.02164452093692e-08	5.54540465271538e-11	7.47280621190082e-10	-2.93839904430733e-10	3.60658741504051e-07	-2.27314217186113e-08	3.07221849868459e-08	1.63606363715694e-10	7.50317584899407e-10	-9.64214208669632e-11	3.65950838935299e-07	-2.22602622183909e-08	3.16641956823605e-09	1.81228263568791e-10	7.59258684937204e-10	1.05612398949466e-10	3.60166698741223e-07	-1.85495439881304e-08
-1.50411486292207e-08	5.83558489864239e-07	-2.04605143112627e-08	-1.37209673833316e-09	-7.09653697900512e-11	3.65221524784373e-09	-2.17263381442592e-08	7.35340682199476e-07	-2.21488913895049e-08	-3.68578964581487e-09	-1.87522593303351e-10	3.24114993582009e-09	-2.22602622185929e-08	7.91568787872354e-07	-2.49809473107789e-08	-4.40252789724911e-09	-2.19862365855565e-10	-8.03338283539586e-10	-1.28100070022144e-08	6.89221184971151e-07
2.27508077138558e-09	-2.21565565711633e-08	3.43646163429808e-08	6.33565161940717e-11	4.30795196082818e-12	-1.44420664707220e-11	2.42466362637398e-09	-2.33641804935264e-08	3.46435071831961e-08	6.70215594168454e-11	-1.80471539473478e-11	-4.18518424102022e-11	3.16641956821771e-09	-2.49809473108718e-08	3.54040276314082e-08	7.01764235234317e-11	1.08584807703397e-11	-4.41705306949284e-11	3.86500134382531e-09	-2.62755292014477e-08
5.08998266378311e-11	-1.46036349767480e-09	6.78878595545626e-11	4.34701276279992e-10	2.79904115196472e-11	-5.52483429664834e-11	1.59025755093255e-10	-3.71231499081219e-09	5.42872965396344e-11	1.22058356343447e-09	8.88175404651449e-11	-4.65083941209257e-11	1.81228263569274e-10	-4.40252789724833e-09	7.01764235233811e-11	2.82955458725984e-09	1.72557303180453e-10	1.82704202202530e-11	2.16827623046118e-11	-2.60335537517938e-09
7.35592497477138e-10	-6.55275941130801e-11	1.56927587198836e-10	2.75780794356793e-11	3.93472545836096e-11	-3.37784740323805e-12	7.49949375417793e-10	-1.95793125777536e-10	9.78734212713035e-11	8.92850271129213e-11	-7.93438089784584e-11	-2.50797392263277e-12	7.59258684937375e-10	-2.19862365855229e-10	1.08584807703583e-11	1.72557303180452e-10	3.17171312398712e-10	1.72011526210266e-12	7.37098952218238e-10	-9.04254755268285e-11
1.64378433262459e-10	-1.30683725608595e-09	1.50923000172512e-11	4.42260486804383e-12	1.47324908742001e-12	-3.64319630028272e-11	2.24074497973588e-10	-2.35950158696059e-09	-2.34743082419399e-11	3.15485751136785e-11	2.87711136829583e-12	-3.00226119639894e-12	1.05612398949461e-10	-8.03338283538727e-10	-4.41705306948583e-11	1.82704202202513e-11	1.72011526210234e-12	9.85304668395987e-11	-4.42277941760844e-11	1.16333442362982e-09
3.54560674790922e-07	-1.10191105554018e-08	5.99424102846489e-08	3.69431658454348e-11	7.33942614057819e-10	-1.19667813242919e-10	3.56302082753370e-07	-1.27171200877633e-08	3.08820328444444e-08	2.84994769413042e-11	7.27773344056533e-10	1.83091308727651e-13	3.60166698741156e-07	-1.28100070023421e-08	3.86500134380002e-09	2.16827623049751e-11	7.37098952218022e-10	-4.42277941760294e-11	3.68315665272456e-07	-1.70339354406870e-08
-1.31215746003486e-08	5.40004460878439e-07	-2.03680063346909e-08	-1.24087539226858e-09	-2.71725494440965e-11	1.78034756805778e-09	-1.62123724740641e-08	6.23793130033510e-07	-2.30743445571644e-08	-2.11221283723928e-09	-6.42461727033928e-11	2.15157500137820e-09	-1.85495439886669e-08	6.89221184971287e-07	-2.62755292014313e-08	-2.60335537518070e-09	-9.04254755280503e-11	1.16333442363027e-09	-1.70339354408992e-08	6.94213867084590e-07

B_R:

1.03175870178633e-11	-8.79189553052589e-13	1.59080116742470e-12	2.41621405638158e-15	1.86501722980406e-14	1.75366390056084e-15	1.03015258408236e-11	-8.46789116527407e-13	8.68678582458295e-13	-2.24360437230112e-15	1.78152395185980e-14	3.83377709016405e-17	1.02911879350126e-11	-8.68517875894631e-13	1.98882940613445e-13	-7.66868893630347e-16	1.80768784756857e-14	-1.15335552306608e-15	1.02832608622751e-11	-9.35051442530130e-13
-8.79189553052589e-13	3.07933014329677e-11	-5.33779632938920e-13	-6.73116062869727e-14	-2.11096786035912e-15	5.06288499645210e-15	-8.77534823669352e-13	3.10119430876808e-11	-6.33107580772930e-13	-5.72750476585272e-14	-1.36275575411084e-15	4.26119772787913e-15	-8.58980396148295e-13	3.10660190503380e-11	-7.32115747563086e-13	-5.66762567173829e-14	-1.02637635181665e-15	-1.73706942711061e-15	-8.31427403738532e-13	3.08967475380148e-11
1.59080116742470e-12	-5.33779632938920e-13	6.80081216548998e-13	1.67237428831680e-15	3.18450275041731e-15	-2.25342161992527e-16	1.58968123534381e-12	-5.54043072699924e-13	5.61778214330174e-13	-2.13701339994040e-15	2.80097939571704e-15	-6.64976529070739e-16	1.59020011907950e-12	-5.78759312660347e-13	4.50862065740340e-13	-1.75201577457165e-15	2.89626592960965e-15	-6.22844231739234e-16	1.59045868464300e-12	-5.98693289728591e-13
2.41621405638158e-15	-6.73116062869727e-14	1.67237428831680e-15	1.69839597204020e-16	8.06257956537145e-18	-1.79450462577336e-17	2.42558213172486e-15	-6.80793259088731e-14	1.86076272565477e-15	3.37129879193649e-17	-2.83829117045900e-18	-1.59839338809655e-17	2.39455453891153e-15	-6.83940868161955e-14	2.05027481277136e-15	6.47752416750080e-17	-9.79577591755958e-19	-1.47964767262689e-19	2.33959226469519e-15	-6.81324290509276e-14
1.86501722980406e-14	-2.11096786035912e-15	3.18450275041731e-15	8.06257956537145e-18	3.77545202946311e-17	2.71620310354043e-18	1.86177206991257e-14	-2.07488756141497e-15	1.77837650125942e-15	-1.70115916793987e-17	3.34622101556667e-17	-3.75185636758635e-19	1.85960462667111e-14	-2.12139614900033e-15	4.75060130985000e-16	-7.06698644505299e-18	3.48892199263426e-17	-2.05724402977358e-18	1.85791363911028e-14	-2.23902549610310e-15
1.75366390056084e-15	5.06288499645210e-15	-2.25342161992527e-16	-1.79450462577336e-17	2.71620310354043e-18	6.91028308356056e-17	1.59537346777557e-15	7.97160556584950e-15	-3.93072902749984e-16	-2.52322583272137e-17	2.71899624296322e-18	6.70190257914095e-17	1.48508091324466e-15	9.86912906944127e-15	-5.62193762595592e-16	-2.63098066039009e-17	2.81973530627402e-18	3.34120902897812e-17	1.43579582353904e-15	1.05007821174212e-14
1.03015258408236e-11	-8.77534823669352e-13	1.58968123534381e-12	2.42558213172486e-15	1.86177206991257e-14	1.59537346777557e-15	1.02861749361966e-11	-8.51318400091087e-13	8.68853093671712e-13	-2.22323221334048e-15	1.77849304648435e-14	-9.91568736846405e-17	1.02762726382151e-11	-8.76896387641732e-13	2.00214055060591e-13	-7.41998084289500e-16	1.80476465723590e-14	-1.22102399755875e-15	1.02685833471280e-11	-9.44694398689834e-13
-8.46789116527407e-13	3.10119430876808e-11	-5.54043072699924e-13	-6.80793259088731e-14	-2.07488756141497e-15	7.97160556584950e-15	-8.51318400091087e-13	3.13592439957615e-11	-6.57539577667682e-13	-5.83505610933747e-14	-1.31924406837513e-15	7.39257482256016e-15	-8.38092019200837e-13	3.15085210860475e-11	-7.61072518925006e-13	-5.76376349842803e-14	-9.67458812822737e-16	1.42976476519421e-16	-8.13775885142815e-13	3.13822730405345e-11
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