Ciao Graham and John
I have reported the problem, which does not seem to be universal. I am wondering if there is an IP block for a number of failed logins. In a similar situation I have turned off and then turned on again the modem which generally forces a new IP to be issued. Though I have to say that I can find no reference to such a feature in the settings.
I can't devote much time to it today but will get on top of it as soon as possible.