For a specific problem report like this, it's best to start a new topic in the appropriate category...this is more a general discussion topic.
Take a quick look in the Mobile Apps/Android to see if anyone else has posted w/your same issue , and if not, create a new topic there.
FWIW, I can use the new mobile app to access and control my devices via the Devices and Dashboards tabs when I'm on mobile data (Wi-Fi off)...
But please start a topic in the correct mobile apps forum I linked to above for the best help and so the HE mobile developer will be most likely to see/track your post. Thanks!
Perhaps a moderator can move the post over. Honestly I don't use dashboards anyway so it won't affect me either way. I was just trying to share a result the easiest way possible.