>>/36489/
The most likely culprit is noScript.
I would divide the needed scripts into two large groups:
1. scripts needed by the site to work
2. scripts needed by the stream to work
In the first group goes everything 1st party cytube stuff. Then - what I see from uMatrix - there's two CDN-s, bootstrapcdn.com and dmcdn.com. I dunno if they are absolutely necessary, but I think they are there for accelerating the service, for me, in uMatrix it is turned on.
Then in the second group belong all the embedded streaming services (youtube /googlevideo???/, vimeo, dailymotion, twitch, etc etc), and remote storages (e.g. endchan, femto.pw, whatever users post for me to drop in the playlist).
Not everything has to be enabled all the time ofc (we probably won't stream from twitch for example), but for the stream to work, the source need to be allowed, and the source can change. You can check all the scripts in the noScript's menu, you can also ask, what is the source to allow.