helix ultimate add to cart problem

-- HikaShop version -- : 6.5.0
-- Joomla version -- : 6.0.2
-- PHP version -- : 8.2.20
-- Browser(s) name and version -- : chrome latest, firefox, etc.

Hi guys!

I’m experiencing a reproducible issue with HikaShop 6.5.0 (updated from 6.2.0) when used with the (latest) Helix Ultimate template.

On product pages with variants, the add to cart function always adds the last variant in the list, regardless of which variant is selected by the user.

This makes the variant selection effectively non-functional.

Variant selection works visually in the UI
However, when clicking “Add to cart”, the system always submits the last rendered variant
This happens consistently for all products with variants

When switching to the default Joomla Cassiopeia template, the issue disappears completely and variant selection + add to cart works as expected.

Could you please confirm if there is a known compatibility issue or required template adjustment for Helix Ultimate?

Thanks in advance!