Chekout as Guest - Users can´t fill information in mobile web version

[GeekMods]

Hi everyone!

I´m helping two friends with their personal shop and this is what they told me that happened.

Suddenly the mobile version of the web can´t let the users fill the first 3 rows of personal information without adding any new modules or configuration to the website.

I´m getting a bit confused, since i can´t see any code error.

If anyone can take a look and give some thoughts, i´ll be really thankfull.

https://sick-pete.com

Thanks!