Xamarin Android GPS speed issue

We have a small Xamarin.Android app which displays a simple GPS speed (used in vehicles), but after Android 9, we are experiencing inconsistent data (sometimes we get speed, sometimes we don't, seems random).

we are using the https://github.com/Xamarians/Xamarians.Geolocator

the event GPSService.Instance.PositionChanged is not triggered, which it should when device is moving.