RBR20 can log in web, can't login using app

Hi,

New issue with a long time setup. Have an RBR mesh at home, normally use mobile app to check on anything and now for some reason can't login using it. I verified my password etc and access by logging in using web portal with no issues, so password is good.

Tried some basic troubleshooting:

Hard powered everything (Routers, app, computers, internet router - everything)

Re installed app

Reset the admin password

Firmware is up to date (Not been changed recently)

Running out of ideas on what to try next, not terminal but annoying. Nothing has changed to cause this, just started happening today for some reason, or at least only noticed today, but as I say nothing changed my end for some time, can't rem last time I upgraded firmware which would be about only thing I would periodically change. 

Thanks in advance,

John