Screen mirror to TV missing audio

When I mirror my Zoom screen from my Android phone or Windows PC to my TV - either by Miracast or by HDMI cable - the TV gets the video but no sound, audio stays on phone / PC. This only happens with Zoom - other apps, from my Android phone / Windows PC, the TV gets both video and audio. When my spouse uses Airplay to mirror Zoom from iPhone or iPad to Apple TV box (which feeds into same TV by HDMI cord), TV gets both video and audio. I've seen a couple other posts about similar issues with no replies. Does anyone know what is happening here? Thanks.