Adding product variants removes main product description

-- url of the page with the problem -- : www.windowtoparadise.com/store/product/8281-ohana-sunset
-- HikaShop version -- : 2.6.3
-- Joomla version -- : 3.5.1
-- PHP version -- : 5.5.38
-- Browser(s) name and version -- : Firefox 50.1.0

Hi,

Adding variants to existing products removes the main product description which is then no longer visible in the front or back end. Variant descriptions are left empty.

Thank you.