It seems odd though, that it has shown an exact location for at least 7 hours now, in the (unmoving) wrong location, and the actual location is a daily workplace where the phone has been showing up accurately for months.
One of the phones on our Apple ID suddenly is showing the incorrect location--10 miles away.
3 replies
Location is determined by a number of factors, one of which is Cell tower triangulation. Depending on landscape, building materials, etc. the triangulation may not be entirely accurate and can sometimes be off by many miles.
Another factor is proximity to known WiFi networks. Since the database of WiFi networks is not updated in real-time, this can also often be incorrect.
You should check location on the phone itself. Open Maps to ensure GPS works correctly
find my iphone displaying wrong location