I forgot to report on my fix to this problem.
I deleted the playlist off of the USB drive and plugged it back into the bike and started her up. After the radio booted, it played the last song like usual but it did not have a track number at the bottom of the screen. When the song was done the Radio said "playback stopped" and did not do anything else. After two reinserts of the USB stick the radio finally reverted back to random songs from the USB drive.
So, for right now, until I can make multiple playlists, I am not doing that again. Deletion seems to be the only fix right now to make a playlist stop because just pulling and reinserting the USB stick does not work to interrupt the playlist.