so ive had my mini 3 pro for about 3 months now and ive noticed that when i let go of the sticks it doesnt just hover in place, it kind of slowly drifts to the left mostly. not a ton but enough that i have to keep correcting it. i fly mostly in a big open field near my house so its not like theres a ton of wind. happens even on pretty calm days.

calibrated the IMU a couple times and it seemed fine after but then a few days later its doing it again. im using the RC controller that came with the bundle. not sure if its a controller issue or the drone itself or what. anybody dealt with this before

compass calibration is probably your issue. IMU and compass are two different things and people mix them up all the time. go into the DJI Fly app, find the compass calibration option and do it away from anything metal, cars, power lines etc. i do mine in the middle of a grass field and it usually sorts out that kind of drift. also worth checking if theres any firmware update pending because there was a version a while back that had some hover stability weirdness on the mini 3.

had the exact same thing happen to mine last summer. turned out one of the props had a tiny crack i couldnt even see properly, only noticed it when i held it under a bright light. replaced all four props and the drift was basically gone. they're cheap enough that its worth just swapping them out and seeing if that changes anything before you go down the calibration rabbit hole