In the mobile version of the site on an iPhone, the field with entering a phone number works either correctly or not, and it says “You forgot to enter your phone number”, how to fix it?

Question

safari

In the mobile version of the site on the iPhone, the field with entering the phone number works either correctly or incorrectly and says "You forgot to enter the phone number" although it has already been entered.
I think that the problem lies in the browser, because the site is on a core i9 computer with 8 cores and 3200 RAM, lags in safari, but does not lag in mozilla

spoiler

The website carmig.ru