Symbolic matlab: Problem with solving easy set of coupled algebraic equations

I want to solve a system of coupled equations for the variables XDD.

I tried the command (the dimensions are the same).

solve(F==0,XDD)

Even in the case with two equations F(1)==0,F(2)==0 and two variables XDD(1),XDD(2) and an obvious easy solution, this returns empty sym:

F(1)= XD9*XD1^2 + 2*XD10*XD1*XD2 + XD9*XD2^2 - 2500*XD9*XDD(1) - 2500*XD10*XDD(2) - 2500*XD7*u1
F(2)=XD10*XD1^2 + 2*XD9*XD1*XD2 + 3*XD10*XD2^2 - 2500*XD9*XDD(2) - 2500*XD10*XDD(1) - 2500*XD8*u1

I checked that there is an explicit solution for XDD(1) and XDD(2) that do not depend on the other variable and can get it via a sequence of subs and solves but do not see a way to get it automatically.

I appreciate if you could point out any mistakes.