(Windows) Basecamp only transfers route start/end point to Nuvi 2450

As suggested earlier, I downloaded an OSM, extracted the MacOS zip file, placed it in the Programdata\Garmin\Maps file, and used Javawa to change the names, id and foldername to “Eastern Europe OSM”. I then installed the map from BC to the SD card of my Garmin in a Maps folder. The only maps in the Garmin are the US map, and the Eastern Europe map, with only the latter checked. I’m using Windows 10. I’m in the US, if that makes a difference. I am also using the latest version of BC (4.7).
I mapped several points in Basecamp, created a route from these points with the Eastern Europe map checked, and Sent To the Garmin Nuvi. (Prior to the export, I deleted all the files in the GPX folder in the Garmin). Basecamp showed that it was downloading to the Garmin.
AT this point, I have my first question, which is whether I am supposed to close BC, eject the Garmin, which turns it off, and then turn on the Garmin? That is what I have been doing, and then I press Trip Planner, which shows the hourglass, and then the trip shows up. Or, do I leave it plugged in (forever) with BC running? OR just close BC, eject Garmin, and not turn it on?
Anyway, by following the first option (although I have tried the others with no more success), I find that the route appears in trip planner, but with only the start and end points showing. However, all the other points seem to be in the Favorites folder.
Also, both the Eastern Europe map and the City Navigator North America maps show up in Windows Explorer (the North America map is called “gmapupdate.img”, and also has a “gmapupdate.gma” file, while the Eastern Europe map does not have a “.gma” file. Basecamp shows the Eastern Europe map in the dropdown Maps in the title bar, but, when I connect the Garmin, it shows the City Navigator map in the left-had window under the memory card, but NOT the Eastern Europe map.

Any suggestions as to what to do/try would be appreciated, as I have to do this for multiple routes.