Comment 6 for bug 1875408

I got the same issue after updating from 18.04 to 20.10 (I did following update in one go 18.04 > 20.04 > 20.10, kernel x86_64 Linux 5.8.0-28-generic).

I had issue with Logitech G604 using dongle. Buttons G4 and G7 (two buttons on the side, closest to the back of the mouse) stopped working plus when dongle was reconnected while system was running, scroll up and down was not working after the re-connection.

The workaround for scroll issue was either to reboot whole machine or switch mouse into Bluetooth mode and back to dongle mode.

Thankfully workaround by user Lastique works, both issues disappeared.