YouTube shenanigans "You're offline"

Situation, I use an adblocker and script blocker in my browser (Opera).
Since today, every time I click on any video to watch, be it home page, or suggestions on the right side of the screen I get the below image.
After I reload the page, the video starts playing without any issue.

Half the time I cant go to my notifications either, since the button either doesn't appear or doesn't respond when I click it.
I already have cleared my browser cache and cookies. I logged out of my account, rebooted both browser and pc.

But when I start the pc and go to YouTube again the problem remains, I did not log in to YouTube yet. I tested with turning off both add and script blocker without any results.

When I used a clean install of Opera in a separate disk location, the videos play without any issues I can rapidly switch between different videos.

So clearly there is still something in my main browser that YouTube is tracking.

Anybody any idea what I should be looking for?

Would be a shame if I need to start nuking my main browser setup with a clean install on a regular basis, since I doubt it will be a one time occurrence.

View attached image.