Dune 3.512 Unison + Bitcrusher change sound

[Sirous]

Dune 3.512

have added a video that shows the problem quickly but I'll also explain here:

There are 2 similar things. If I turn on only unison voice 1 (listening) and add more voices, even though they are turned off and detune and spread is set to 0, the volume from voice 1 gets more silent, the more voices I add. Should it be like this?

But more of a problem is if you add the Distortion Bitcrush and do the same as above, the sound completely changes.