That was happened before 4.2 (and after) for me.

Ended up being that it had nothing to do with the controller (or any wireless adapters at all), but mainly that the code being used for controller support (especially xinput) doesn't always prioritize the controller when there is a lot happening. So having lots of other programs, like a browser with multiple tabs of youtube and an android emulator for a mobile game I also play, combined with having a lot of rendering in FF14 (like in hunts or raids or being in a city, since there are more people/objects) would randomly cause it to just ignore input - which could sometimes mean buttons or new analog movements to cancel out the old movement (and thus cause an apparent "sticky" movement) to happen.

Try closing everything else and extra background programs.