malfunction on iPhone

Hello, on iphone it does not work correctly in full screen
Either using safari, chrome or another browser on iphone, when you search for the 2nd time the search engine does not appear.

If I lock the iphone screen and unlock it, the search engine appears.
i have tested on iphone 8 plus, iphone 11 and iphone 12 for max. in all the same problem

in this link I leave you an image with screenshots with the problem

https://tolseniberica.es/erroriphone.jpg

Thanks a lot!

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