@krillechill I dont think the method at which I exit fullscreen matters. The matter of fact is that when exiting once the browser re-enter fullscreen. I am allowed to exit fullscreen again, but that means I have to exit twice every time I leave a video.
But whatever, I went down my list of possible video-altering extensions and found it do be caused by this extension: Volume Controller. It's quite silly that it'd be that one, but I haven't had issues since I removed it.
The extension itself was quite buggy, but I kind of just dealt with it. I would've just used the top result volume controller extension but I was trying to find one that wasn't too obstructive. I now have the top result Volume Master. While it is obstructive it works as intended.
If anyone else is having this issue, I would recommend disabling one extension at a time and checking if the issue persists.