[SOLVED] USG110 Registration : it remains "not registered"

hello all !
I bought an old USG110 with unused licences attached. I registered it on portal.myzyxel.com, I can se it, with associated licences (426 days remaining).
But on the GUI, it remains "not registered". I tried to reboot, to wait, ... It's well connected to Internet so everything is there to allow it to access Zyxel database and see it's well registered.
Debug Logs say : "MZC:module=FW_ZYXEL_S, status=standard, change=0, total=353, grace_period=-1, grace_remain_amount=-1, max_amount=-1, lifetime=1, quantity=-1"

Help
Thx