nevw
(Nevw)
6
It may help to download from javawa the device manager and see if it identifies a problem.
http://www.javawa.nl/jdm_en.html
I would then try another map provider and try one of their Garmin suitable osm maps and also read the instructions on that page to check if you have missed something.
https://wiki.openstreetmap.org/wiki/OSM_Map_On_Garmin/Download