@iamlamprey Thank you for your help!
I don't know why. I redid some other elements of my code and suddenly it worked.
So yes for now its working properly in Hise itself.
I finally solved this mystery, so here is the answer for anyone else who has this problem.
My MIDI keyboard for some nonsensical reason outputs on multiple channels at once. This causes duplicate notes to be sent to HISE which causes the group counter to increase twice for each key press. So the solution is to filter the incoming MIDI channel in HISE preferences.
Are you testing the exported plugin with the same sine wave you used to test in HISE? In your previous version that didn't have this issue were you testing with the same sine wave and were you using IPP with that one?
@Christoph-Hart It looks like somehow I need to insert Parametric Curve Eq module between encoder and decoder because there are only one band filter nodes in scripnode and making full featured EQ in scriptnode is definitely not what I want :)
I have an idea is to split the signal on Mid and Side using decoder + ms_splitter + routing matrix nodes, then insert two Parametric Curve Eqs - one for Mid and one for Sides. And then add another sciptnode with encoder node. Basically I'm making the initial snippet but with scriptnode.
Just want to confirm if that possible with scriptnode and I'm thinking in the right vein.