Many thanks for your detailed error description.
For us this issue unknown and not clear what causing it.
Please zip your song folder from the USB drive (including the wav files; midi file and the .set file) /please use some file sharing service eg wetransfer etc/ and send it to support_at_cymaticaudio_dot_com email address
We are going to take a look at this problem.
Are you able to reproduce the issue every time?
Is the delay happens all the time at the same place? If yes please tell us the exact time too.
I’m looking forward for your message