some songs not transferred

I"m transferring songs with iTunes and some won't transfer. They are .mp3s,

I"m selecting a playlist in Garmin Express to transfer.

If I look at the upper part of Garmin express, where it shows my iTunes library, and look at the particular playlist, the song count is incorrect, for whatever reason Garmin express is showing say 50 songs, but there really are 70 songs in the iTunes playlist.

Has anyone else had this issue?