Epic Failure - I think you are spot on. I encountered that during the Tour de France, sometimes I wouldn't turn it on on Peacock until about 5 hours into the race, and it would only go back so far. Maxim was watching a 6+hour stream of rugby, so similar problem. Fortunately, handball matches are only 1.5 to 2 hours.
Another thing about Peacock, which should seem obvious, and that is when the live stream ends, no matter where you are in the event, the stream stops and you get the message that replay will be posted soon. So I've rewound the handball match, I'm at about the 45 minute point in the match, and then suddenly without warning it stops.