3 (Probably Simple) Mapbox Map Issues

I am using Mapbox in my app and three issues are coming up. Two are related and the other is separate. Let me know what screen shots would be helpful if anyone wants to see my workflow or keys, etc. I am very new to this… so I apologize if my issues are a bit naive.

The first two that are related:

  1. Mapbox zoom will start heading to my location and then end up about 30 miles to the east. After 5-10 seconds it will correct and center the map and zoom on my location.
  2. If I browse around on the map, maybe click and hold and go south a bit down an interstate, after a few seconds the map will recenter and reset the zoom level to my location and predetermined zoom level in my workflow. I can’t seem to get this to stop.

The unrelated issue:

  1. I am having trouble finding a reliable way to add lines GeoJSON to my mapbox. I would like to show bus routes in a given area. Ultimately, I want to be able to interact with the lines like I can with markers.

Thank you to anyone who can help me or guide me in a reliable direction to resolve these issues.