Thanks for chiming in. Maybe you are referring to this post: MIDI FX for Logic Pro X: Burst of unexpected MIDI data arriving at processBlock in first buffer
This seems to be about the NPRs that are sent in the first block. I can confirm that these are also sent to our plugin, and the latest version of the Cthulhu MidiFX as well. They don’t cause any trouble.
But the poster of the above does not see the random messages after the NPRs that we see - which is the problematic part.
Edit:
Also worth noting that Cthulhu does not produce the random messages, which seems to indicate that this could be a JUCE problem.