I can’t seem to run the Android target “Build and run” with physical device?
Just to make sure:
Have you tried starting adb logcat manually?
I’ve come up to some distributions that mess up the permissions, thus not allowing Unity3D (and others) to recognize / connect to the devices as normal users.
As a TEST, try runnig the ADB daemon as root, and then starting Unity. If it works, it’s a permission issue.