@gokhanyildiz I solved this also by adding a third enrtro into product_attribute_values table with text value 16,17. As a result I have three entries with text_value "16" "17" and "16,17". This way customer view filters the product with "or" function and the admin view shows all the assigned options. So I am aware there might be some other issues by manually interpreting with DB. I just wanted to point out where should be focused.
I couldn't go further yet in the source code to have an implementation but I think either if we can update the comment to insert or read comment responsible for product_attribute_values table we will be developing this feature.
Any guidance will be highly appreciated