Choose Affected Attribute Set prompt when saving configurable product

[Aquive]

I use Big Bridge product import to create configurable products. Everything works as expected. But when I try to save a configurable product, I get below prompt. I does not matter if I have changed any data or not. After that, it does not matter which option I choose, I allways get the same prompt again when I retry to save the product after choosing a prompt before.

I am not sure what is going wrong. Any idea's?