@Marinus-van-Deudekom Thanks for that, Marinus. I had downloaded the files to the phone, but they were in the phone's memory, not on a memory card. Interesting, though -- it seems like the issue could somehow be speed of the connection between the two devices. I will have to ride around a little more to see if the problem is a regular issue.
I was using MRA entirely in offline mode. The area (in Mexico) where I was riding has very little connectivity. I wonder if that might be a factor too.
Thanks again,
Vinnie