I get the error only when I connect from my local network wifi. If I use my smartphone from a remote location everything works fine.
Tado does not support WiFi. You need to connect the bridge to your internet router using a cable.
The bridge is connected to the router using a cable. As I said everything works fine when I connect to my Tado from outside my lan (i.e. Mobile networks) when I try to connect from inside my network I get the connection error.
I get the same error repeatedly. Keep hitting retry and eventually it works - can replicate on multiple phones. There's no network issue, it's Tado.
Are you both using the same model phone perchance?