I use Brave to play YT videos. It works as long as I don't open videos via links posted in other apps, e.g. from Telegram. Once I use a YT link forwarded from another app, it requires a YT log in and won't play the video. Solution: close brave session (delete session history if not done automatically), use new VPN location (change IP address) and search video in brave/YT directly. Maybe it's the same with Newpipe.

yeah, this sucks. Usually I wait for the next update and it's fixed. Seems Google is regularly changing something which breaks the newpipe playback