Jhieminga good idea, tried it in Edge, exactly the same problem - main account has the problem, sub account doesn't...
netstruggler I just have a single Google and YouTube account...
Oddly enough I was able to see the live chat OK on the Flyer Livestream using my main account last night but only AFTER watching a David Gilmour short (I tried this three or four times - open the livestream, nothing, click on DG - which showed likes, etc, - then go back to Livestream, there we go...) - but only the chat, video details, likes and so on were missing. All works fine on mobile phone, both in Chrome and the app.
There was an issue a few weeks ago where the Youtube Interface had been rearranged - it took some fathoming out and everything resolved itself eventually - I know not how...
Cheers chaps, I'll see what happens. I hate all the settings as you seem to go round and round... who programs this stuff?