My configuration.yaml has default_config: which as I understand it includes the mobile.
I'm supposed to respect my elders, but it's getting harder and harder for me to find one now.
Surely it has to be a misconfiguration somewhere, if you can access the page through the browser using the same address.
Maybe try explicilty enabling the app in config (see here), and double-checking the SSID that you're connected to is in the list.
