If I am making a metadata preset for a location I use frequently, the saved preset does not have the same GPS accuracy as the photo it is derived from. That is to say, I place a photo in the Map Module to set the GPS location, and then use the information attached to that photo to create a preset for the photo's location. When I then use the preset, the Map Module shows the photo in a slightly different location. It appears that storing the GPS data in the preset rounds off the GPS data slightly.
Work around: Use the preset to get close, then move the photo to its actual location with the Map Module.
I filed a bug report on this: Lightroom: Latitude/longitude improperly rounded when stored in metadata preset | Photoshop Family Customer Community . Please add your me-too vote and opinion to the bug report to make it a little more likely that Adobe might fix this before the next ice age.
Unfortunately, LR has a number of issues handling GPS coordinates, the Map module, and track logs.
Also, the bug report contains another inconvenient workaround.