Can’t get Full screen from YouTube

[Susja]

Hello,
I've got a new monitor Acer 29.5” 12:9
Everything is working fine except video streaming from YouTube
Any video clip I try to play from YouTube has cut of picture from both sides. In other words I can’t get full screen from YouTube. When I try to play any other Video sources I do have Full screen
I have checked all settings on YouTube and on monitor but can’t find anything relevant to it
I am using MacBook Air 2020
Could anyone help?
Thanks
P.S. I also noticed that YouTube does not have Mac version .. hence the only option is browser. I tried Chrome and Safari browsers ... same issue

 

[Susja]

Folks,
Never mind.
I found the solution by installing extension and now I'll all set

 

[Gregg2]

Is it a YouTube extension or something else?

 

[Susja]

It is Chrome extension Ultriwide