Xbox Elite controller 1st generation?

I have had the Xbox Elite Controller for about 1 year, everything was perfect, but now it only occurs to me at Rainbow Six Siege that my operator (character) slowly creeps forward. Does anyone know why and whether you can do something about it?

Maybe it's because of the game I recently played on the Switch Fortnite again and my figure always moved by itself

Spray some contact spray on the stick, I had that too.

On my switch the left stick is sometimes not quite in the middle, that you always move forward / up. However, it is so minimal that you can't see it when looking at the left stick

This is due to the looped trigger on the left. What you can do about it is unscrew and remove the plastic covers behind the trigger or otherwise oil. (Please be careful with the technology.) But I advise against it if the controller is still under warranty.

That could be because of Joy Con, my girlfriend and I also had it on the switch and it got worse and worse. At first it was very rare, then continuously.