How to pin a Wordpress page on IOS (mobile) so that it does not jerk up and down when swiping in the gallery?

Question

iOS

I am attaching a video of the behavior of the site page on Wordpress when swiping images in the gallery.
https://youtu.be/tOTKssW4LoE

How to properly block header mobility when swiping images? The page looks generally unstable when it follows the trajectory of a finger across the screen.

I'm not a developer, I'm a user. However, previous experience in hiring specialists with kwork and fl has already rewarded the need to roll back to a backup, since attempts to "pin the page" caused damage to the desktop version.

I would like to get the answer myself in order to correctly set the task for the future performer in the future.