Yep, same here.
All the same problems that everyone else is having with online videos. I even found the gallery couldn't play videos.
Started to play after reboot last night. Nothing plays again this morning.
S21 5g ultra. Uk
Exact same issue.
Been having a lot of problems since the update, only had this phone for a week before the update. Videos don't play, sometimes clearing cache works but 15mins later it doesn't. They also broke Google Calendar, for some reason some events have white text but others have white.
They have a lot of things to fix. Until then, let us revert an update!
I have a possible work around solution for this:
Settings > display > motion smoothness > standard
After changing this it seems to be working ok, possibly some changes to the adaptive in the 4.1 updates thats causing the issue. Not ideal but should get you by until a patch.