How can I use the same email for multiple stores and solve iPhone viewing issues?

[Voli]

I have a Shipify site with 2 stores on one email address and another store on different email address trying to put same email on all stores and once login can select which one i want, the 2nd store says that email is already in use.

And when a apple phone looks at our site it freezes and not able to view page, only Iphone

Any help ?