Would have thought several of us here would have noticed, as I have done over the years since the maps appeared, the number of errors on them.
The track shown always seems OK, the coastline is distorted in places, but the various cities shown for location are often way off position. These must be stored with erroneous coordinates in a database in the system.
Also often notable is the wacky range of cities chosen for location purposes.
From a computer technical person's point of view, it is a typical US-developed system (I believe Honeywell are the main suppliers). Good basic concept, developed rapidly, sales and marketing very good. But the actual application is poor for useability and accuracy, and the glitches don't get updated. European IT companies tend to get these the priorities the other way round.
Glad the flight deck don't use it for navigation ! (by the way, many passengers believe that it does come from the aircraft's priimary navigation systems)