When you reinstalled MC, did you also restore a MC backup so that you got back your library and all your settings? You should have. MC automatically makes backups. Restore the last one made before the Windows 10 upgrade.
If after the restore of the backup TV still doesn't work, run the TV setup process again.
Can you still play recordings made before the upgrade?
Your AVR changing inputs would be something to do with your remote controls. MC can't do that. Theoretically, connected devices can send commands to other devices, via
CEC or similar depending on your hardware, but I doubt it is that. Do you use a Harmony remote? Have you programmed it to select the input on the AVR?