Problems with app URL connection

Hello! I am supporting Nabu Casa and had no problems til now. It automatically detects my server when it starts: and detects the Nabu casa integration. In local wifi I can use my HA with no probs.

When I use data internet, there is no way to connect. It says connected though internal URL and I cannot modify the external URL (which is blank) because it says it cannot be modified as it will be automatically detected with nabu casa.

Any thoughts?

Ps. Location services are allowed. My HA instance is available though internet when I use nabu casa URL. iOS 14.