Heres the reply I've got from my hosting company
Thanks for your reply.
Unfortunately this does not explain how ZenCart itself performs the check on whether Apache .htaccess Support is enabled.
Sadly what you will need to do is contact the ZenCart support in order to find out why the Zen Cart fails this test.
What you may find is that the Zen Cart test is calling the Domain Name from within the hosting, which creates a loopback call which sadly is not permitted by our Firewalls, which would block the test resulting in a fail. Unfortunately if this is the issue, this is something that we cannot enable as it will be detrimental to the shared hosting platform.
I can confirm that all of our servers have .htaccess Support enabled, so its likely down to the Zen Cart itself, which would really need input from their support.