Simple center_on command displays blank map on android

[krchug]

Describe the bug
Using plyer gps, obtain gps co-ordinates of the phone. A simple center_on of the mapview makes the map go blank.

To Reproduce

Create a simple gps class to get the current location

class GpsHelper():
    def run(self):
        # Request permissions on Android
        if platform == 'android':
            from android.permissions import Permission, request_permissions
            def callback(permission, results):
                if all([res for res in results]):
                    print("Got all permissions")
                    from plyer import gps
                    gps.configure(on_location=self.print_location,
                                  on_status=self.on_auth_status)
                    gps.start(minTime=1000, minDistance=0)
                else:
                    print("Did not get all permissions")
                    request_permissions([Permission.ACCESS_COARSE_LOCATION,
                                Permission.ACCESS_FINE_LOCATION,
                                Permission.INTERNET,
                                Permission.WRITE_EXTERNAL_STORAGE,
                                Permission.READ_EXTERNAL_STORAGE], callback)

            request_permissions([Permission.ACCESS_COARSE_LOCATION,
                                 Permission.ACCESS_FINE_LOCATION,
                                 Permission.INTERNET,
                                 Permission.WRITE_EXTERNAL_STORAGE,
                                 Permission.READ_EXTERNAL_STORAGE], callback)

    def print_location(self, *args, **kwargs):
        print(kwargs['lat'])
        print(kwargs['lon'])
        app = MDApp.get_running_app()
        print(app.root.ids.mapcode)
        #marker = app.root.ids.mapcode.ids.MapMarkerPopup
        #marker.lat = kwargs['lat']
        #marker.lon = kwargs['lon']
        app.root.ids.mapcode.center_on(kwargs['lat'], kwargs['lat'])
        app.root.ids.mapcode.zoom = 13
        self.stop()

    def stop(self):
        gps.stop()

call it in the main app

from kivymd.app import MDApp
from mapcode import MapCode
from plyer import gps
from gpshelper import GpsHelper

class MainApp(MDApp):
    def on_start(self):
        gpsmanager = GpsHelper()
        gpsmanager.run()
MainApp().run()

Works perfectly. The map gets recentred on getting the location when deployed on android. but then it goes blank and then even if i scroll or move around i see a blank map

Expected behavior
Should see the recentred map

Logs/output
No suspicious logs from logcat

Platform (please complete the following information):

• OS: [e.g. windows 10 /OSX 10.12 /linux/android 8/IOS 12…] Android
• Python version.
• release or git branch/commit

Additional context
Add any other context about the problem here.