AliSLR I've set up a development server on a Raspberry Pi 4 using RaspiOS, and installed Tvheadend 4.3-2723 from the Cloudflare package. This of course has the new UI.
If I open the Electronic Programme Guide and click on a currently-running programme, then from the pop-out menu select Play -> Play in browser, the programme plays in a pop-up window on both Chromium and Firefox provided I select "webtv-vp8-vorbis-webm" profile. If I select Play -> Play in external viewer, on Chromium a full-size player opens in another browser tab but it doesn't work (there is no activity in the Tvheadend log). On Firefox, VLC opens and the programme plays - this may be because I've changed the settings in Firefox.
If I go to Configuration -> Channels and click on the play button, on Chromium the full-size viewer again opens and fails to play. FIREFOX invokes VLC as before.
Sorry I'm out of ideas.
