Controler faults and directional issues

So I’ve had a Phantom 3 Standard for a couple of years but haven’t used it in a few months. Took it out for a flight a few days ago and found that it had a controler calibration issue (constant beeping from the controler). I updated the firmware and supposedly successfully calibrated the controler and it seemed to be working fine.

However, I soon discovered that when strafing left to right the drone would get locked on full speed in one direction and no matter where I moved the stick, it wouldn’t stop. I managed to land it roughly but when I looked at the display when calibrating the controler a second time, I found that the strafing function was faulty and reading that the controler was 100% in one direction despite the stick being in the opposite direction. The values to either side seemed to change randomly. All other directions seemed to work fine other than ascending and descending which was overly sensitive but still functional.

Has anyone come across this issue before? Or know how this might be fixed? Or will I need to replace my controler?

I would do a full firmware update (controller, drone, battery) direct upgrade from DJI before looking for a replacement controller. Some people have downloaded SDK files not knowing whether the controller’s previous firmware version will still be compatible with the new drone firmware. And buying another controller might not work unless it also receives a firmware update. I haven’t done a firmware update for ages and my Phantom flies like when it was new. (With Litchi of course)