Variants

Hi,

Without a link to the product page nor seeing all the settings of the variants, I can't confirm, but I would say that the problem might be the modifications done to the product page layout.
Try to rename the folder templates/YOUR_TEMPLATE/html/com_hikashop/product via FTP. If that solves the problem, then yes, the problem comes from the modifications done to the product page layout on your end (or in the template).

Hi,

Well, the link you gave confirms what I thought:
take.ms/82cZr
The characteristic, quantity, contact, tags and id areas of the product page layout have been moved inside the price area on your website.
That is not the case by default.
And that's what is causing the problem when the characteristic selection is changed as it updates all these areas, but then the HTML of the variant for the price area only contains the price and thus you loose all the rest on the right side.
Normally, renaming the folder templates/YOUR_TEMPLATE/html/com_hikashop/product via FTP should fix the problem.
If it doesn't, it's either that the modifications have also been done directly to the files in components/com_hikashop/views/product/tmpl/ or that you have some caching on your website and that your didn't clear the cache after renaming the folder and thus you still saw what was generated with the template overrides activated.
So please check that.