Dhcpv6 client doesn't complete negotiation, no delegated prefix

I think I found the culprit. I started disabling services, like sqm, mwan3, modemmanager, removed the LTE dongle and after I disabled banIP I have a couple of successful ifup wan6
What puzzles me is why didn't it have any effect after I stopped the firewall with fw3 stop
Maybe @dibdot can help us understand?