Netgear Nighthawk X10 / R9000 won't recognise admin pass & pass reset doesn't work

Roger. Yep, checked the differences between AP mode and router mode and AP mode does disable some nice features that I'd like to keep. I'll get in touch with Vodafone again to ask them how to configure their router in this case.

Also, in regard to the password thing on the router. I just went ahead and did another factory reset - all well, set it up and everything, but then after some 10-20 minutes I get a pop up (while being on the router admin page and checking settings) to log back in into the router and by putting in the details I just set the router up with - they are no longer accepted. And neither are the secret answer questions for password reset accepted. Is this RAM inside the R9000 going qooqoo or...? This almost looks like someone gaining access to the router and doing this manually but this seems really unlikely as nothing else has ever been compromised i.e. I don't think I have ever had accounts hacked etc.

Anyhow, thank you for your help!

EDIT: Attached a file of some of the router settings.