Troubles with treble, bass and mid control.

Dear Sir/Madam,
I’m a blind person and I’m trying to use DjayPro2 on MAC-OS with the VoiceOver app to navegate through the software.
I own a Pioneer DDJSB2 controller to control the software, however, I found some issues with the mixer. When I fully close the bass potentiometer, treble and mid - I noticed that both do not fully reducy the frequencies.
I’d like to know if what is happening is really an issue or there is a setting that I need to set up - Because I didn’t find any setting while I was navegating into the software.
Besides that, I couldn’t find the settings to turn off the Cross Fader - because I don’t really use it.
I’m also found some buttoms without labels while navegating with VoiceOver on the Samples Screen.
Thanks in advance,
Renan Dal Pont Cardoso