I have reset the router (for other reasons), and the tether app is now working. It feels to me to be very poor software design, if the only way to fix an app for a mobile device to manage a router is...

@tppatron Ok, thank you. It seems rather poor, that a software update to an app requires a full reset to factory of the router, when the app is the only thing that changed. And, it would also be good...

@Solla-topee Ok, does that mean, that as mine is a V1 you can do nothing?

@Solla-topee I've attached the two screenshots requested. The Router I have does not require a username, only a password. I have set the password to a value of '1' (single digit only) and get the...

@Ver0nica Thank you, but for me it didn't change anything. I am still unable to logon to my router through the tether app. I also tried clearing all data for the app, setting it up afresh and setting...

@TPuser333 I tested with both iPhone and Android, and more than one device. I even set the password to be '1' no way to type that in incorrectly... but... no change.