I use a USB C phone (Nexus 6P) with the mavic. When i plug the phone in the RC, the defult USB profile is that the Phone is charged by the RC.
I dont want that. I just a data connection with the RC.

So Android lets me choose a different USB profile like PTP, MTP, MIDI etc.. However as soon as i change the profile the RC doesnt communicate with the phone.
if i unplug and re plug the phone, the default USB profile kicks in all over again and im stuck in this cycle. im just trying to prevent RC wasting its battery to charge the phone when i dont want it.

I just downgraded my DJI Go app back to 3.1.2, and everything works again. Try it... https://www.apk4fun.com/apk/124176/

I'm having exactly the same issue. All fine when the phone is wel charged, and luckily it doesn't use quick charge, otherwise it would drain the RC in 20min, but still it is a pain as none of the other works without getting a disconnect.