I downloaded the Battlenet app from Google Play.
After choosing Log-in the screen flashes to that page, but then just as fast is replaced by a “Hmm…something went wrong.” screen. I have tried all countries.
Android Q S10+.
I have a large host list that blocks ads and trackers on my device but doesn’t affect any apps that I have ever used.
The battlenet app has a few trackers:
Google Tag Manager
Google Firebase Analytics and
These are blocked from connecting outside my device for obvious reasons. I doubt that has anything to do with the apps failure but added as a long-shot.