May be partial user problem. A common problem is IF a GPS sits for an extended period of time with dead batteries and the clock function defaults as a result the unit will loose reference information. On turning on it will be confused as to where it is in the world because they do store a certain amount of information as to what satellites will be in what location on a give day and time to help them acquire satellites faster. Now they will eventually reset from the satellite signal but it may take a while as that information is coming from 20+year old technology and it has a slow feed. Often the quick fix is simply setting its clock and that will allow it to update off the satellites at a much faster rate. I learned that the hard way after not using my old GPSV for several months sending it in and it came back as "no trouble found" and a note saying "if it ever happens again set the clock".

More info right from the source.
https://buy.garmin.com/support/produ...d-000000000000