Cannot Save (route name) Garmin / BMW Navigator V

I downloaded several European maps from OSM. Some are ‘national’, and some are custom with selected segments.
JaVaWa GMTK reports some overlapping segments. I’ve renamed and changed Map ID.

I have Base Camp 4.7.0 installed, so I can’t use Map Install to upload semi corrected maps directly to GPS.

I have copied gmapsupp.img to the SD Garmin/Maps folder.

I used JaVaWa Device Manager to correct map names, but I can’t change the Map ID, which the custom maps share.

I used Base Camp to make routes. Nothing complicated. Some with start and end points, some with up to 6 shaping points.

Some routes will import into the GPS, but half of them refuse to import. No idea what’s wrong. Get a message “Cannot Save (route name)”.

Any suggestions?