If you’re using a Logitech mouse with the unifying non-Bluetooth receiver with Mac OS Catalina, things seem to work just fine. However, with Bluetooth, some security settings get in the way.
I had thought that my fancy Logitech mouse, the MX Master 2S, was broken because it won’t scroll iTerm2.
The workaround is to uncheck “Secure Keyboard Entry.” (or switch to the non-Bluetooth setup).
You can read more about this issue here: