Do OSM Downloaded Maps with Garmin BMW NAV VI Require Default Maps be Disabled?

I’m doubtful that this is the place to pose this question, but I’m not getting answers from Garmin, or MyRouteApp (MRA) software groups.
I have been using MRA for a few years and have a new NAV VI with the latest and greatest software. It seems to be working well.
I am doing a tour of the ALPs the end of June. Rather than buying Garmins maps I downloaded and installed the OSM maps for Central, Southeast and Southwest Europe. Installation seemed to go well. I have not disabled the default Garmin maps of N. America.
I have exported a couple of sample routes from MRA using both the OSM and HERE maps. I have tried to import the tracks, and convert it to routes, as well as importing the route directly in the Trip Planner. I have been able to open the routes, and see the waypoints and view the map. However, when I hit “GO”, the screen “Calculating the route” comes up and shows 0 %. This may change to 5 or 10%, but will never actually complete. I have let it run for hours.
Clearly not solely a OSM/Garmin/MRA issue, but any ideas would be greatly appreciated. Could this have to due with having too many maps installed on the NAV VI?

Thanks in advance.