Frage Is this normal for a Collet/Nut pair?

I bought a collet and nut for my MM-1000 from Stepcraft. I thought i would get a Maffel nut/collet similar to the one the spindle originally has. Yet i received a Kress nut and collet.

My problem is that i already had a kress collet 8mm that i expected to snap in the nut. But what happens can be seen in the video. The collet does not snap and lock to the nut.

Is that a problem? I gues it is a problem because when i will try to remove the bit the collet will stuck in the spindle. But why does this happen? Both are supposed to be Kress products.

photos.google.com/share/AF1QipNhwZfD4RNcbjs1Sdzs8jqoyY8t95lMjEkuhqtlePVuZQuI6KwB8BVtKRUZdrFSHQ?key=R3VNeHVJbGt5dVpEeE9rSzZvSUdWdXZZY3VWWUhn

Can't see the detail of the nut in your video; but one direction to look into is that there are two types of nuts for Kress that will physically fit. One difference is in the collet retention afaik. They also look different. Have a look here: www.sorotec.de/shop/Spannzangen/KRESS/

The one offered for Mafell also looks like the later type for Kress: www.sorotec.de/shop/Spannzangen/system-mafell/