Hi
I also noticed and reported the issue when the "Backgound notification" icon remain in notification area.
This can happen in couple of cases:
1. Just start OsmAnd, Open map and after that enable sleep mode when the background service will keep GPS turned on to track and follow even if you switch to other applications or take a call.
If you exit from OsmAnd it will warn that there is a background service running and would you like to cancel it. Even if you click yes the background service will be turned off but the icon will remain in notification area.
The only workaround for this is open OsmAnd back, open map, enable and then disable sleep mode.
2. Sometimes this icon remain in notification are when during the navigation you will decide to exit OsmAnd before reaching the destination point. To clear the notification are you must do the same steps as above.
Regards,
Areg