Youtube shortcuts on firefox

Tonight I noticed something really weird when I tried to reply to a comment on Youtube. Initially, I tried to reply from the bell button in the notifications and soon I realized that the Spacebar was not working. I thought it might be stuck, but it was not, since it was working fine in both the address bar and the search bar. Asynchronous keys function was disabled. Then, I went to the video and tried to reply from there. Guess what! The video was being resized using the shortcuts depending on what I was typing! For example "t" changes between normal and theater mode and "i" makes it picture-in-picture. What is going on? I am sure no key is locked, i even restarted my pc and the same thing kept happening. Then, I turned it off and on and the problem was persisting. Everything works fine on other applications, just YT seems broken for some reason. I tried to type on YouTube on two other browsers and everything worked fine. I don't think it has anything to do with the windows update, since it only happens on firefox, which I don't intend to change. Is there any setting to lock/toggle the Youtube shortcuts on and off? Sorry for the length of my description and thanks a lot in advance!