@dc42 I think i found it! Evidently there is a bug:
https://forum.duet3d.com/topic/15207/duet-wifi-wlan-vs-wpa2-connection-error/8
https://forum.duet3d.com/topic/14993/cannot-connect-duet-wifi-to-new-wifi-router
@bearer You aked me if its a vodafone and its not, but in one of the post it says its an Arris router and mine is Arris too. I gues this freaking router has something that is not compatible. Just for starters i can't turn off dhcp nor update the router's firmware wich is BS. So i guess by now i'll just use it on AP mode until y buy a proper UNIFI Gear.