Hikashop checkout register guest login buttons not working on phones

-- HikaShop version -- : 3.1.1
-- Joomla version -- : 3.7.3
-- PHP version -- : 7.0.16
-- Browser(s) name and version -- : iphone safari, android etc..
-- Error-message(debug-mod must be tuned on) -- : no error message

Hikashop checkout register guest login buttons not working on phones.
system works ok on browsers outside of phones.
i cannot choose the options on the iphone.
only the default i set will work.
at the moment i set the default to guest as that is usually what most customers want but the other options do not work and they are displayed correctly there but just cannot choose them.
i had a recent issue with users unable to choose the add to cart and have resolved that issue with adding ajax in the akeeba admin tools
here: www.akeebabackup.com/support/admin-tools...king-updatecart.html
as that fixed that issue but now further down the line we cannot use mobile options for customers.
your help is much appreciated.