After reset, not all filter options are displayed

Hello, I have the following case.

1. I select all product options, so that I can put my product in the cart.
2. I click the “X” to reset the filters.
3. Now, not all product options are displayed anymore. Only after site refresh they are back.

For example, you can test it at this produkt: https://zielfernrohrmontage.com/produkt/atv-korn/
Or you can watch this video: https://www.swisstransfer.com/d/2d3b7145-2fa0-4015-8169-bf1457841175

A second thing. Is there a possibility to have an auto-select? So if the user select the first product option, that it automatically select the first option of the other filters?

Thanks and regards
Sebastian