Google Maps navigation is dropping during screen off

My Google Navigator now dropping navigation if I turn my screen off. Before that I was able to navigate by audio hints from my pocket, now I am unable to do this. Once I turn my screen off, navigation stops. Moreover, when I turn my screen back on, navigation doesn't continue automatically. First it tries to trace a route again and requires me to press "Start" button. Power saving options are OFF, Maps application has Location, Notifications and Physical activivty permissions granted. How to fix?