When sharing a YouTube video, all iOS users get either the notification “this video doesn’t exist” or they see the video thumbnail with a play button on top but the video won’t start.
The problem occurs in the iOS App as well as browser-based video conferencing with Jitsi in Safari.
After playing 3 videos that won’t show, it suddenly works. This was the case for all our iOS users (4 people with 4 different devices, some with app, some with safari).
We also tried to replicate the problem the next day and it was still exactly the same. To share YouTube videos with iOS devices, you first have to start 3 videos that will fail and then it will work. But after a few more videos, it starts to fail again on some devices, we weren’t able to replicate when exactly it stops working again.