Jamtrack distorted, cracking?

[BigAl]

I am quite competent with audio, interfaces, jamkazam.  For some reason I am experiencing major distortion with the one single free jamtrack - wish you were here.  JK sessions otherwise sound fine, everything else sounds fine, just he jamtrack comes in crackling (not audio-level clipping, but rather a crackling).  I have solo'd each instrument on the track, they are all crackling.

Any advise?

Thanks!