Hello,
This behavior is a side effect of recent patches that we had to integrated into HikaShop product edition system.
Due to JS issues with some browser and modifications in the TinyMCE lib during Joomla updates ; we add to include some patches in order to avoid these issues. Unfortunately, one side effect is to toggle automatically the variant editor so the user need to click on the "toggle" button to switch the editor back.
Because we do not have the full control on the editor, it is hard for us to provide a code which will work with every editors with every browsers.
The variant edition is special because its content is loaded dynamically in Ajax ; so the had to find ways to make the editors to be loaded dynamically (and not generate conflicts with the main product description).
So, we will investigate and see if we can improve it. But I have fear that it will re-generate the JS issues during the save.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.