size not changing when selecting different variant

-- HikaShop version -- : HikaShop 2.6.0
-- Joomla version -- : Joomla! 3.4.1
-- Error-message(debug-mod must be tuned on) -- : When changing the product count the size doesn't change.

I see the sku number changing but not the size right underneath it

When changing the product count the size doesn't change.

I see the sku number changing but not the size right underneath it

The size is a custom field. If I unpublish it, it disappears from the back end but not the front end even after I clear joomla's cache.

Hi,

That's normal. That's not a default thing displayed by HikaShop. That area of the product page has been added (either by you or your template provider) and it wasn't made to be able to support characteristic swapping.
Instead, you should create a custom product field. It should normally update itself automatically unless the default display of the custom product fields has been customized as well.