When flipping the screen of a mobile device, the font size changes, how to fix it?

Question

Adaptive design

With two flips of the screen of the mobile device (to the horizontal position and back), the font size on this site (loveyou.ua) changes. For clarity, go to the useful information or contacts section and turn it over.
I would be glad if someone suggested a solution, since the problem itself is unusual.

UPD 1
Maybe only on iOS?
UPD 2
I confirm - the problem is only on apple phones.

Answer 1

html {
    -webkit-text-size-adjust: 100%; /* Prevent font scaling in landscape while allowing user zoom */
}

Answer 2

I don’t think that without markup, styles and scripts that process screen rotations, it will be possible to identify the problem.