I think you’re having some trouble with English here…
the tab with youtube in the edge?
We can’t suggest or replicate what we don’t understand.
switches to the first plan by itself
Also hard to understand.
If you are discussing Edge internet browser, this is a rather unpleasant proprietary application, which is known to have certain behaviours - as such, not a bug but a Microsoft Special Feature.
So the solution - don’t complain about Edge browser (if I’m right) and use Firefox instead.