I tried doing that but it didn't solve my problem. :(
I contacted Facebook twice, but no answer from them.
Is there any other way of solving this?
I'm seriously considering removing all the products and after that posting each product manually, with only the lowest variant. Which is crazy, because I have over 100 different products...
Following your instructions, I found another way to do in bulk instead open one by one.
Thanks for the great idea Chris95!!