Do you mean the “Follow unit on map” feature?
Please check that the data on the change in the unit’s location is received in a timely manner. You can do this in the unit menu - Tools - Toolbox - at the bottom of the section with messages.
If messages are not received, then write about the problem in more detail at firstname.lastname@example.org.
If data is recieved timely, please make sure that the “Follow unit on map” button (the button with the “arrow” icon on the map or on the unit card) is enabled (displayed in yellow). The function turns on after selecting a unit, but it turns off when you, for example, zoom in on the map, then press the button to turn the function back on.