|I killed the communication between my PC and my Android phone a while ago. The phone won't work with my portable, nor with my desktop. It lost them both ad the same time, so it wasn't the fault of the PC(s) - and I know how I did it:
I am not a big fan of smartphone apps. My eyes are too old, my fingers too large, and touch screens everywhere refuse to react to my fingertips - if you see someone at the coffee machine tapping, tapping harder, tapping again, ... then it could be me. Same with my baking oven. And my desktop radio. I set up my Bluetooth PC keyboard to talk to the phone, but that works at home only.
I decided to clean up my phone, so that it would have only the apps that I "must" have. Not the other hundred or so apps that somehow have made it into my phone. I killed off every one that I didn't remember ever using. Obviously, I removed one too many.
I haven't yet gotten around to fixing it, but assume that a complete 'restore to factory settings' will do the job - crossing my fingers for factory restore still being available even if OS updates no longer are. If not, I have another reason for replacing my six year old Galaxy S7 edge with several cracks in the front glass