rncbc
commented
3 years ago what MIDI instrument are you driving this? tested with several external synths as (internal) plugins, all polyphonic and with sustained voiced notes (eg. organ, strings) and I can't see/hear what you're talking about;
no note seems be dropped whatsoever as they keep playing right from start to end--most are 5min long, right?
I tried importing and playing back the following MIDI file which Ardour plays no problem:
https://filebin.net/kw3jd9ljimahh2sr
After a few seconds, almost all of the notes start dropping.