Locus map lost GPS signal after 1-2 hours of tracking without recover

Hello.

I am facing issues related to the GPs signal. The xiaomi note 4 is in the bag with screen off and always with GPS active. All track is recorded but after the first hours GPS signal in the app is off. I need to open locus map a seco de time and then GPS is on again. This is only happens with locus. With other apps, do teu have issues. The app works properly the first hours always but in a specific moment lost the GPS.