Installed this and was working for a few hours then I got the Youtube pop-up. Changed a few things, cleared the cache, updated and tried again. Now it's working and I can watch Youtube without any pop-ups or limitations.
When I installed this, it was mentioned to add a filter which you can find the details on here:

https://www.recover-android-data.com/video-player-will-be-blocked-after-3-videos-on-youtube

Scroll down to Fix # 3.