Copying takes a long time

Sometimes when I copy a MIDI event, Cubase stops responding for 10 seconds or so. If I attempt to paste the event, move the cursor, or otherwise take an action before the ~10 seconds is up, my action will either a) happen after the ~10 seconds or b) not happen at all.

In particular I’ve noticed this behavior only on the MIDI events on certain tracks. Most commonly it is on MIDI events that exist on an instrument channel that has a “heavy” load. My strings instrument tracks each have 8-10 articulations loaded from EastWest Hollywood Strings into Play; that’s a “lot” of data, and my copy actions exhibit the behavior described above. However if I attempt to copy MIDI event data from a different instrument track that only has only a “little” data, like only one articulation from a lighter EastWest library loaded into Play, I do not experience this copy behavior.

Has anyone else experienced this? Or do I just need to trash my preferences or something?

I just trashed my preferences. No change. Any Idea what’s going on?