If you play with a foot pedal on PB, and have wrong polarity set it would be something like that.
I tested to a Kawai piano and see nothing strange about it.
And to have something like that on a particular preset is nothing I ever heard of.
It would be always or never, kind of.
I had a UC33 controller connected to computer once, and created midi ports over usb.
That had a firmware update to fix a similar thing, while nothing played it had wrong polarity so last note hung.
If it's always high(current on) when resting, and it was the other way around. Long ago, so don't remember.
I would look for firmware update on Genos, maybe.
Or look if to turn off something in PB it is sending, like aftertouch or something.
And a certain preset could have settings for aftertouch that could explain if just some presets.
There is nothing wrong with PB in general that I could find.
To check if midi port is ok, you could connect midi in to midi out on PB, and set local off when playing on PB.