Arduino gamepad joystick float

So I have this game controller I made. it has 4 joysticks, uses a nano, and is programmed using the linked project

This github project is excellent, easy, awesome, I hope the heavens rain gifts upon it's creator.

anyway, I still have a problem. The game controller works great at first, but over time the center of the sticks changes value. So, at first I thought it was whacky loose breadboard wiring, but over time I have become very confident I know which behaviors are from that,, and this behavior appears to be different. I suppose it still could be that the resistance of some connection is changing somewhere, but it appears to be a gradual float that happens when I play for a long time, say in excess of 10 minutes. So, every ten minutes I need to recalibrate the joysticks.

I have ordered parts to solder a replica of this one together, but it will be some weeks. I suppose if the problem goes away then I will know for sure it was just breadboard connections.

what else could be going on??? could the stick potentiometers be polarizing?? could they be loose internally? is there some other problem?? I thought that perhaps the controllers on the market have some kind of automatic calibration, but I don't know,, the arduino is just sending raw potentiometer values to the serial feeder, and I calibrate the center manually, which seems to be a normal thing??

thanks! Here's some pics. Also, I will link a video demonstrating it in game. If you have comments about the design of the controller, any aspect, I am also happy to discuss.

How is the project powered?

it plugs into the computer usb

Okey. Half an amp from USB ought to work.
Hook up a digital DMM and monitor the 5 volt.