Hello,
“Can you help me please? I can’t solve the problem.” – I’ve changed settings of the Wishlist plugin on your site. Please clear cache and check the result.
“I also wanted to let you know that 2 days ago my site suddenly went “crazy”…8 copies were created for each product. luckily I had a backup copy and I solved it but what happened is not normal. Why?” – It seems you activated “Show Variations As Simple Products (Beta)” in Theme Options > WooCommerce > Shop > Products style.
Regards