Greetings. I recently purchased and received my Samsung Galaxy S21. It is a fantastic phone. I used a USB-to-HDMI hub with all the functionality of the Samsung dock for Dex to connect the phone to my HDTV. The desktop mode looked great on the television, and I was able to play YouTube videos over my phone in much the same way I would on a laptop. BUT... the sound was coming out through the speakers on the phone, not through the television speakers. I tried this on another known good television in my house and got the same result. While in desktop mode, I went to Settings/Dex Settings to look for an Audio Out toggle or menu. Dex Settings did not contain any menu items related to Audio at all, much less to Audio Out selection.
The hub I'm using as a substitute for Samsung's S21 dock is very modern and designed on the same principles as the Samsung dock. It is designed to connect the phone to a television through HDMI, with audio and video going to the television over HDMI. It is rated at 4k 60Hz, so I'm sure it is very modern and not one of the compromise models that don't always work.
I'm hoping this is an issue that can be fixed by discovering some setting or OS app that hasn't turned up in my recent, exhaustive Google searches for this problem.
Can you help me get audio out to my HDTV over a USB-to-HDMI hub?