My family has currently a fiber connection with a very basic gateway that doesn't offer a IPV4 gateway address - only IPV6 gateway available. I had trouble connecting other WIFI routers there, as they expect a IPV4 address and just refused to work. At the end I needed to use a rental WIFI router of the provider, but the WIFI signal is too weak to cover the whole house.

Would it be possible to use DECOs in router mode? Can they connect if no IPV4 router address is given by the fiber router over DHCP?

Thank you very much for your kind support!