Issue with Beat Sync on XDJ-AZ

Sometimes when I have the Beat Sync button turned on certain songs will slow down to what sounds like 10 bpm and the bpm will read in the 600's for a few second before the drop of certain songs. All the songs I have were downloaded legitimately, analyzed normally not dynamically, my firmware is up to date, and I have the same issue with other USB flash drives. The waveform will zoom in a ton for those few seconds, and then return back to normal.