Once it's reset the specific config no longer exists. It will simply be on defaults, on 192.168.1.1/24 conflicting with the Vodafone router. Your current problems most likely relate to fact that you have two DHCP servers operating on same network. If it is indeed connected via its LAN interface then it's not routing anyway and serves no purpose.
There is no vodafone router involved when the ubiquiti router is installed. I'm not using two routers at the same time.
I understand I lose the current settings but I can't get them without the password anyway.