it is not that evident on the videos that you're using linuxsampler as a plugin on ardour (must be lv2) or qtractor (maybe lv2 or dssi).
i suppose you're using the auto-monitor filtering facility in qtractor (current track monitoring). however, one thing i should ask anyway is, from the qtractor part of the video, one can see that se a MIDI closed loop to the MIDI controller:
iii You Rock Guitar -> Qtractor(in), and then, Qtractor(out) -> iii You Rock Guitar
is that last ALSA-MIDI feedback connection to the controller really necessary? does it also apply as same connections (JACK-MIDI i suppose) when you're using ardour?
note that, when in (auto-)monitor mode, all incoming MIDI events on input will pass-though to output as is (in fact, that's exactly what the MIDI monitoring concept is in qtractor, kinda an internal MIDI-thru).
maybe, just maybe, the MIDI feedback loop is interfering with the controller, triggering note-off events (or else) too early?
i'm puzzled by the reported behavior, as you probably are. but you can try to record some phrases into a MIDI clip, on the MIDI track where the linuxsampler instrument plugin is inserted, of course, and after that, rewind and playback what you've just recorded and verify whether it sounds the same as loosing note release tails or else?
it is not that evident on the videos that you're using linuxsampler as a plugin on ardour (must be lv2) or qtractor (maybe lv2 or dssi).
i suppose you're using the auto-monitor filtering facility in qtractor (current track monitoring). however, one thing i should ask anyway is, from the qtractor part of the video, one can see that se a MIDI closed loop to the MIDI controller:
is that last ALSA-MIDI feedback connection to the controller really necessary? does it also apply as same connections (JACK-MIDI i suppose) when you're using ardour?
note that, when in (auto-)monitor mode, all incoming MIDI events on input will pass-though to output as is (in fact, that's exactly what the MIDI monitoring concept is in qtractor, kinda an internal MIDI-thru).
maybe, just maybe, the MIDI feedback loop is interfering with the controller, triggering note-off events (or else) too early?
i'm puzzled by the reported behavior, as you probably are. but you can try to record some phrases into a MIDI clip, on the MIDI track where the linuxsampler instrument plugin is inserted, of course, and after that, rewind and playback what you've just recorded and verify whether it sounds the same as loosing note release tails or else?
hth.
cheers