help with envelope firing on note off

I have my Sub Phatty setup so that if I am holding a note and then I play another note, it will trigger and reset both the filter and amplitude envelope. GREAT! BUT…

When I have a note held down, then I play another note (so far all is fine), THEN I let go of that second note, the envelopes fire again! It’s driving me mad.

When I play a note while holding another that second note fires when I immediately press it AND when I let go of it. So the enveloeps are triggering on note off commands.

Someone please tell me how to fix this?

Cheers,
Ian