@Lindon Ok well more investigations..... and a "work around" solution....
So you need to put your Hardcoded Polyphonic FX in an Effects chain in the same container as your Gain AHDSR envelope, and add a small (around 100-150) ms of release and this clicking goes away....
So for example lets say you have this structure:
2201b459-a17a-4291-a850-4dcd9d00ca65-image.png
You must put your AHDSR envelope (here AHDSR Envelope1) in the Syntesiser Group1 where you must also place your Hardcoded Polyphonic FX
Put the FX down in the Waveform Generator and leave the AHDSR where it is? - nope no worky...
Put the Poly Hardcoded FX down in the Waveform Generator and leave the AHDR where it is? - again - not gonna work reliably....