A follow up on these things.

It's clear now they are faulty and do not do what they claim.
Maybe we were unlucky and just got a bad set, who knows.

We tried them on a D3100 and D3300.
12mm...works on both, AF, aperture control, etc
20mm dead on both.
36mm dead on 3100 and works sometimes on 3300 if it locks in.