Here is a simple example How to put my location on a map. If you code the example, does it work properly? If you can display the location successfully, it indicates your gps receiver is working properly. If it works, you can discount issues with your gps.
With respect to your app
How are you passing the location coordinates to the second screen? You must pass the geocoordinates to the additional screen. Did you add that feature after Aug 29 or make any other changes to your app?
Do you have your Map component on the first or the second screen or both? You cannot show the marker on the second screen unless you pass the coordinates.
You provided the community a fairly detailed explanation of what your blocks are supposed to do (but currently are not doing); a copy of your Blocks image would help diagnose the problem.
Of note, sometimes the panTo block does not do what the developer expects using the OpenStreetMap tiles (top set of Blocks) (the pan glitches and you do not get the expected response) ; I recommend to avoid glitches to use the bottom set of Blocks which does the same thing.
and is more reliable code.
Make sure you have these set
in your Android Settings.