Hello! I can answer to me from someone who knows the cause in C8 after you record a midi track with an external instrument (Yamaha Motif XF), playback is heard sooner or later. VST instruments that are PC written and have no problem of delay in playback. In C7.5 recording and playback midi has no problem.
I’m having the same problem
Updated the Motif editor today and got things working again and now this.
It may be a good idea to just put in a support ticket to Yamaha or Steinberg
Whoever wants to take responsibility