My screen won’t rotate when I turn it sideways

.

Odd … oh well …

Here’s a C&P w/o the images:

Lock or unlock the screen orientation

You can lock the screen orientation so that it doesn’t change when you rotate iPhone.

Open Control Center, then tap .

When the screen orientation is locked, appears in the status bar (on supported models).

Sounds like Rotation Lock got turned “on.”

See if this helps:

https://support.apple.com/en-au/guide/iphone/iph3badf94ec/ios