Expression Maps dynamics problem


I have a problem with sudden dynamics jumps connected to MIDI events.

I work with a big orchestra template, where the bulk of the libraries is handled by Vienna Ensemble Pro 6. So, Cubase 9.5 is only doing the MIDI stuff, in connection with Expression Maps. Now, sometimes certain MIDI events are suddenly too low in volume, and then they jump back to normal. Always at the same spot. It is as if some kind of automatisation is going on somewhere (which is not the case). BUT: If I stop the MIDI event before it ends and I re- play it, the volume is ok all over. And, to make it even weirder, the same volume jumps happen to more than one MIDI event at that spot.

Let´s say I play a certain line on violin I, violin II and cello. I switch via Keyswitch/ Expression Maps to Portato (for all instruments), and then towards the end, to tremolo. Then I replay it: The volume one the first bar is super- low on ALL instruments (even if the modulation curve is maxed), then it suddenly jumps to 100% volume.

In my opinion it must be a bug in the Expression Maps, because if I take the MIDI events and load the same articulations as single tracks, without Expression Maps, all works fine.

I hope I could describe the phenomena somewhat clear enough. It doesn’t happen too often, but often enough to be really annoying. Grateful for any advice.