[BUG?] YouTube universally not loading fragments.

[ObscenityIB]

Describe the bug
YouTube started annoying me with constant buffering again, so I gave FastStream another try, as it didn't work for me a few weeks back, and it still didn't work for me today.

Interestingly, even with FastStream uninstalled, YouTube is still giving 403 errors to video fragments in their own player.

I even replaced my network card thinking it was on my end, and it did not resolve YouTube's constant buffering and rejecting fragments in its own player.

Is there something that is left behind that messes up YouTube in this way?

Version
FastStream v1.3.35
FastStream v1.3.36
FastStream v1.3.37

Platform
Firefox 134.0a1
Firefox 135.0a1

Steps to Reproduce
Watch any video with either FastStream installed or not, fragments will start getting denied access regardless.

Example Video: https://www.youtube.com/watch?v=FLst31H5T6g&t=379s

The timestamp is just there because every time YouTube buffers, which is every few seconds, I have to right-click, copy the timestamp, and then paste it into the address bar to force it to load more of the video.

Refreshing the page doesn't work because it forgets what point I am at in the video and goes back to the start, which is another YouTube issue unrelated to FastStream, I don't know if FastStream's local timestamp storage works, as it has yet to actually play any video.

YouTube Player:

FastStream Player:

[Andrews54757]

It might mean that you have been IP-banned by Google. Try changing your IP address.

[ObscenityIB]

It might mean that you have been IP-banned by Google. Try changing your IP address.

No dice there, same thing, also affects chromium, which I only use for sites that refuse to work on Firefox.

yt-dlp seems to work fine using the same cookies Firefox is using.

Clearing site data and logging in again didn't change it either

Searching around more online, it seems to be a common consensus that YouTube is running tests to block 3rd party software, which is even more weird that their own player doesn't work, but yt-dlp does, and so does a modded android client.

Edit: Also found that alternative frontends work fine too.