Problem with add to cart (urgent LIVE site)

Well its hard to explain thats why i uploaded a video.
In some cases the POPUP does not display
IN some cases the POPUP displays – but the added items are removed from cart after 1-2 seconds.

When You`ll watch a video notice ALSO that in 20 second of the film the product UPSELL was not added to cart.

Untill yesterday we were using BUNDLED PRODUCTS (plugin) it was working ok.
Today we moved to standard GROUPED PRODUCTS in Woo, and this happens as i have described above.