It’s likely because some light fixtures that emit a ton of UV light also look “cool” and get used in the wrong setting. They’re supposed to be for stuff like disinfection. Looks like the bulbs outlining the dj both could be the issue. It wouldn’t be any of the professional fixtures. (Pic in comments because I don’t think you can upload an image in this community for the main post)
Here is an alternative Piped link(s):
https://piped.video/vfLZOkn0chc
Piped is a privacy-respecting open-source alternative frontend to YouTube.
I’m open-source; check me out at GitHub.