In the Android app (version 2.51.0-master2), there seems to be a navigation issue on most screens after you return to the app after enough time has passed that Android tore down the Activity.
You can simulate this more easily by turning on Developer Mode and enabling “Don’t keep activities”. The problem occurs without this though (you’ll just have to wait a while and use other apps).
Use the app and navigate to something other than the home screen (like a shade’s control page). Press the home button. Reopen the app via the launcher icon. You should be back on that shade’s control page and things should still work. Hit the phone’s back button. You’ll be presented with an empty white screen instead of whatever should have been next in the back stack. You have to force close the app and relaunch to get out of this state.
Using the “Don’t keep activities” settings, I’ve confirmed this also happens on the settings screen, usage history, schedules, etc. So it seems like something core to the app’s activity/back stack/restore setup that’s causing this.