After a discussion with support, I found out my magnet was loose on the Y axis.
Using the X axis magnet, I was able to pull out the loose magnet, glue the backside, and place it back in. Afterwards, all drift was gone. The joystick is back and good to go
Workaround: constantly hitting "Start Calibration" to reset my curves seems to fix the problem temporarily. Just annoying to do, and inefficient mid-game.
I'm having a nearly identical issue with a joystick delivered less than a week ago. It flew fine for two or three days, but immediately started having these issues. Here's what my joytester window looks like. unknown.png I have repeated all of these steps, including default settings and disassembly....