Select a youtube resolution and resize the player.
Thank you for the issue report. Unfortunately, I can't reproduce the issue. Everything works fine for me, tested with the latest Firefox + Greasemonkey, as well as the latest Chrome + Tampermonkey on a separate computer. Since I can't reproduce, it would help me a lot if you could provide me with some more information so I can identify the problem.
Can you please share the following?
Operating System
Browser (and version)
Userscript Extension
Any modifications you made to this script
Any other scripts or extensions you have that run on the Youtube website
Also, if you can find any logs in the browser's error console, that could help a lot to pinpoint the issue.
It is also very possible that Youtube has placed you into a experimental change rollout, which either isn't compatible or has a bug on Youtube's end. I believe the rollout is done with cookies, so you might be able to check if that is the issue by seeing if you still get the problem in private/incognito mode (if you gave the userscript has permission to run in that mode).
Are you still having this issue Noah? Or can someone else confirm there is an issue here? If there is an issue, I would like to fix it if I can get the information to do so.
As of 6/14/2022, this script doesn't appear to work anymore. It doesn't apply to Youtube's newest update and doesn't seem to apply any of the settings for quality or auto applying theater mode.