I just got an Enduro 2 about a week ago. I updated all the included maps via Garmin Express, and I can confirm that the version shown in the watch is the latest version of TopoActive/SkiView/CourseView. However, in Map Manager, all of these maps indicate there is an "Update Available". I got tired of seeing that, so I tried to update via the watch, starting with SkiView since it's the smallest. I plugged it in, the map download starts, gets to almost 100% and then shows "Map Sync Failed". It waits 30 seconds, and does it again. Then again, and again, forever.
My OS is version 17.28