I have the Logitech C920 webcam connected to Sony Bravia (850G) TV. I sideloaded Zoom and everything except the Microphone works. For some reason the microphone is not working so no one can hear me.
I read that it could be because of the built-in microphone on the remote. Is there anything that can be done to switch to the webcam microphone to make it work?
you could try and remove the remote from the system, by going to bluetooth settings and removing the device. I use a harmony remote on my X900E, which is IR, I would assume that the remote uses IR as well, and just bluetooth for the mic.
I think you need to check the highest max resolution the Sony TV model can support for UVC webcam profile by using the AIDA64 for Android TV app. For X90H, it can only support at most 720p so it is useless to go for anything higher than that. Therefore Logitech C270 is sufficiently enough even though the streamed video of us on the main view in Google Duo is kind of blurry on a 4K TV. Nevertheless, I have tried Logitech C320 and it still works.
There is nothing you can do.
The problem has been there for years and it seems Google doesn't want or can't fix it, however, for some reason some Logitech webcams work while others don't, but other brands don't work at all.
I have a Logitech C270 and it works with Duo but I haven't test it with Zoom.
There is a bug report (made by me) at Google's Issue Tracker website where many users have complained about this problem, if you want you can add yours to the long list of complaints, maybe one day Google will solve this problem once and for all.
https://issuetracker.google.com/issues/145900984