Has anyone on sertraline had problems with getting prescriptions by different manufacturers?

I'm assuming you mean will a person have a different reaction to different generics even though the drug is the same? Usually not, but different manufacturers may use different inert ingredients as fillers, binders, and colouring agents. Some people may find the the medication is less effective because of poorer absorption potentially caused by some of these ingredients.
Personally I take quite a few medications and they're all generics because of the $$$$$ factor. I've never felt any difference at all with any of them. In fact, I even had a generic once that seemed to work better than the original name brand I had been taking.