Page orientation!

I have a iPhone Max which is up to date.

Question-

Why is my page orientation fixed in on place? This is Totally the opposite and very awkward to what I would usually use it.

Before when I was watching YouTube or

or other videos my picture would automatically rotate. Now it’s only in one position with the sound (top of screen) to the left and the home button to the right.

I hate this!

Is there a setting I can change this in?

Or is it simply a bug that Has to be fixed?