TYB! Happy Flag Day/4-10-20 Birthday!
YouTube functionality broke overnight: can no longer middle-click on a thumbnail, to open it in a new tab.
Now, it shows the "autoscroll" icon, and moving mouse up or down scrolls the view.
To open in a new tab, user now has to aim more carefully at the "title", rather than "title plus thumbnail".
Reported; will see how long the behavior lasts (so, recording here "publicly").