Windows 7 1440p videos switch to 480p @ :10sec mark.

[trog69]

Good evening. I have an issue with hi-def videos. I have a 2560x1440 monitor, and a gtx 780 card, so I should have no problem running videos @ 1440p, but when I go to full-screen the video switches back to the small screen and downscales to 480p at the :10 second mark. Then, when I expand the screen again, sometimes 1440p will not be available, though 2160p or 1080p still is clickable. Mostly though, it works fine after I re-expand the screen and retry 1440p.

This happened just now with a 4k video from a new phone, as well as previously on videos from PC Gamer. I have no issues playing any of my games at 1440p.

Thanks for any help.

EDIT: I forgot to mention that this is via YouTube.