RBR20 Unable to Connect to iPhone App

I have an RBR20 Router with one satellite. I occasionally make use of the iPhone app to manage the network, and that has worked brilliantly.

I've just upgraded to a new iPhone, and the app is asking for my user ID and password. I've tried entering it, but it's saying I have the wrong info. While it's always possible that I've forgotten that I changed this login, I do make use of a password manager. And while the app on the old phone won't show my password, I've gone ahead and entered it in the 'change password' feature, along with a new password. This works just fine on the old iPhone app, as well as the web based login. Yet, I'm still unable to log into the app on the new iPhone. I've gone so far as to delete and re-install the app, in case something was being cached... but no luck.

I'm about ready to get rid of the old iPhone, but it's my only control for the Orbi.

Any ideas would be appreciated!