@ian-street
Hi @Ian-Street use the Garmin gpx1.1 that is the new gpx file that you can use for the new Garmin devices.
Garmin XT, 590, 350 and BMW Navigator 6
With this file you can use the route.
Also the gpx 1.2 file is new, this is a track based route with via points
See also: https://info.myrouteapp.com/blog-routes-loading-garmin-zumo-xt/