OK first things first, Problem solved.
Now what happend.
I contacted the Network provider. They told me the card were not blockt neither the puk has not to be entered.
I went to a provider store they tested the simcard on an other phone and it works fine.
Next we removed the sim pin withe the shops phone. After this the simcard could be used without entering a pin.
When the simcard was put back in the fairphone the phone loged in the provider network as aspected. Final step was to reenter a simpin and everything went back to normal.
Thanks 4 your Help