Youtube are making changes on the api again and this time they are now requesting loging to view videos, this is not related to bot protection or the use of vpn, we test it with over 30 users and everyone are having the same error.
We discover that yt-dlp can have an option to sign in but it would require a workround for VRChat to implement it. Here is the info i found: https://github.com/yt-dlp/yt-dlp/wiki/Extractors#logging-in-with-oauth