When I register to receive Activity Recognition Transition, it is working properly, then I send the app to the background and it's still working properly, I keep the app alive using a foreground service, for other purposes,... after about 36 hours OS stops sending activity recognition transitions to my app, even if I open the app.
This will not be fixed until I clear the Google Play Services cache (which often works), or I reboot the device.
I wonder if it's a bug in Google Play Services, a power saving effect, or what?