Here's an example of how it sounds. First it's 2 notes, then 3, then 4:
Original sound: https://instaud.io/2TNT
With Envelope device modulating the gain: https://instaud.io/2TNU
You can also see how the Gain acts up in this GIF:

Can anyone else confirm this bug?
It makes no sense why it only happens on chords of 3. Is it possible for some Max for Live wizard to fix this in the Max editor or can only Ableton themselves do it?