Digital Filter Changes Results

Why is it when I apply a filter and run the code several times, the output of the fitlered data changes slightly in like the 2nd or 3rd sig fig unit?

I would use a simple bandpass filter at the 10th order and the output would sometimes change. I understand there might be a transient signal, but even if I use the method that's highly recommended on MATHWORKS, I would still see some slight changes. Is it because MATLAB uses the approximation of the filter and that approximation randomizes a bit? Or is it that the transient function still affecting the signal?

I utilize the data filtering function from the built in Filter Designer App.

My code also includes downsampling with the built in downsampling function from MATLAB and don't know if that's the source of the slight deviation in my results.

[Jon]

If you could attach a standalone example that demonstrates the behavior it might be possible to look into it further.