Insert SIM, no sim recognized

20 days ago more or less I move to marshmallow developer preview (I don't know if this info could be useful).
Some days ago I changed phone operator. Before to change the sim they told me to wait the actual sim stop to receive the signal. I happened today. So I changed the sim, inserting the new sim, but it does not work. I mean it seems like the sim is not inserted.

I tried the new sim into iphone of my colleague and it works.

I thought it was for some instability of marshmallow and I just come back to lollipop 5.1.3 (wiped everything except the internal sd) ....but the sim is not recognized....Do I have to do a more deep wipe?
Or what it could be?

Thanks for you help

Ciao

Is that normal that Air Command pops out when you insert Spen?

Hi guys, i recently lost my Spen, and bought another one from unknown source.
Everything is working fine, but when i insert the Spen back into the port,
the air command pops out too. Is that normal?

Thanks :)