Live TV in Browser - which codec? How to select?

I have a tvheadend installation from latest image tag. It is working in general, that means, i can access the tuner hardware, it gets the muxes and EPG is also showing up some upcoming shows. But the UI is quite confusing, and i am a little bit struggling with watching some actual TV.

I have discovered the “Watch TV” button in the upper right corner of the EPG tab. I am somewhat lost with selecting the right decoders, though. The only decoder which shows audio and video is webtv-vp8-vorbis-webm, however, it is stuttering. I do not find any errors in the “docker logs” output, though.

webtv-h264-aac-matroska has only audio, but no video. It is not stuttering, though, so maybe it is more suitable, if i could manage to get video. How could i get it? Can i somehow set this decoder as the default? Is there any reason against disabling the other codecs?

There is some setting in Configuration → Stream → Stream Profile, but i am not so familiar with all the codec settings and do not want to break anything. Is there some general advisory for noobs like me?