Trying to use adb tool 1.0.29 on a PC running Linux Ubuntu 20.04 to debug my Motorola Moto G7 Plus running stock Android 10 (hence not rooted) connected via USB.
Previously it was working OK, I've granted USB Debugging permissions to my PC. But today adb devices shows it as an offline device, so I can't do anything.

Here's a list of actions I tried:

• Revoke USB Debugging Authorization - it doesn't work, nothing happens, Android doesn't prompt for new permissions


• Delete /data/misc/adb/adb_keys on the phone - Can't, no root, adb root and adb shell return error: device offline


• Rebooting, disabling USB Debugging and Developer Options and disconnecting in any order didn't help


• adb kill-server and adb start-server didn't do the trick as well

What else could you recommend?