Thank you for the file.
This is not much help, but, here, in v4.33, the Note Offs are as expected.
Here is your pic, with my MIDI Monitor log added:
... Big pic:
https://i.imgur.com/IaeITjX.png
insertpizhere's Monitor does not show Notes Ons with 0 velocity explicitly. In the screenshot I have included a small section from my own MIDI Monitor that shows that those Note Offs are actually Notes Ons with 0 velocity.
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So the problem started somewhere between v4.33 and the latest version.