You may want to hook it up to a computer and do the DJI Assistant program and see if there is a calibration routine for the mini. You get the same issues if you change items on a hand held gimbal, where it looks like it is mixing a cocktail with you camera. You run calibration and it is again smooth as silk. It needs to get the basic figures reset to your present installation. Try that, you absolutely nothing to lose or hurt by trying.
I just tried this and it didnt help. Gimbal does its little dance and suddenly shoots up and gets stuck lile on attached video. I also trid to calibrate gimbal in fly app but diacovered that there is no feed from camera.https://youtube.com/shorts/G4Ds1Vv7wYA