Hmmm... Linux Mint 20.3, Firefox 117.0, BraveBrowser Version 1.57.57, Chromium: 116.0.5845.163
All 3 Browsers up2date AFAIK - nogo on all of them.
Strange....
Edit: Safari on iPad iOS 16.5.1, same problem...
Edit2: HTML code of the page looks bad:
<embed src="http://www.youtube.com/v/pXO0qmjaMOA&rel=1&fs=1"
Looks like it's encoding the & to &
I guess I found the error - the embed uses http instead of httpS:
Blocked loading mixed active content “http://www.youtube.com/embed/pXO0qmjaMOA?rel=1&fs=1”
Is there a way to re-configure the EMBED tag for the site to https?
Edit: It's definitly the mixed active content. Temporarily enabling the feature in Firefox shows the Youtube video.
But that's a security risk and shouldn't be enabled.