Not as far as i can see...
do you have some of your own code within the page? that may conflict with the arastta code and cause some fallout. May be check the code for some out of place stuff.

here is how it looks from here:
go to:

https://search.google.com/test/mobile-friendly?id=OLV5DUcKQISIZiWlsDIUyg

Not talking about this website. Talking about the arastta store.
Viewing our store on mobile device doesn't appear to show anywhere to do a search.

https://search.google.com/test/mobile-friendly?id=wbs27wemnhs-g2u8_i9hxg

hummm... ok. do other page elements like the brand logo, the nav menu etc. show on the hand held instrument?
on this basic arastta site using the default store here it shows the search box:

https://search.google.com/test/mobile-friendly?id=tHfDTWfSY1pzQzQ3aV8Mag

does it shop up on a PC, or TV etc????

Using Second theme. Must be a glitch with the theme.