@Azostar I don't have a bug, but I do have a suggested feature that might be nice:

If you can make the ability to lock any window in place, that would be highly useful I think. To make it so that you can't accidentally make something unaccessible, you could make it so they are unlocked when you restart Fantasy Grounds.

I have no idea if this is possible, but it would be really nice I think and prevent accidental window movements.