Pianoteq 9 pre-gen playback issue in Digital Performer 11

I have just upgraded to Pianoteq 9 - Standard, and have noticed an issue when using it as a VI in Digital Performer 11.  When Digital Performer is in pre-gen mode, there is a problem with playback of a MIDI sequence routed to Pianoteq 9.  When I start playback at any point where there is note-on data, the first notes played sound very briefly before being cut off, no matter what their duration is set to.  All subsequent notes sound normally.  If I start the playback on a rest in the sequence, all subsequent notes play correctly.  If I record-enable the track or put Digital Performer in "Live Performance Mode", this playback issue disappears.

I don't have this issue with Pianoteq 8-stage or Pianoteq 7-Stage.

Has anyone else had this problem?  It seems to be an issue related to Pianoteq 9, because none of my other VI plug-ins (including previous version of Pianoteq) have this playback problem.