Nope, it might also just be a graphical glitch (the polyphonic filter uses some dummy coefficients when no voice is played which might cause these jumps).
@dustbro Add it as a separate script, you can right click the midi processor and connect it as an external script or just copy and paste it in, whatever suits you. Then just link up the controls on your main interface script to the module's controls. BTW the module is licensed as GPL so if you use it your project source code will need to be available under the same license.