A silly blunder by myself i.e not making a proper record of the new admin password forced me to do a factory reset.
The first two attempts didn't work the router coming back with the previous settings despite the lights flashing saying it was going back to default.
The third one half reset it so I lost the wan connections but it still had the new password.
The fourth attempt finally cleared the admin password as well.
Anybody else had this reluctance to reset to defaults.