SCI waveforms visualization after IC MUXed

Hello,

A hardware genious in my company added a IC MUX (after CT) for sensing 3-phase currents in a current-controlled inverter; the idea is that the signals are multiplexed towards the ADCH19:

I'm utilizing a F2837xD for this design.

In order to send the phases in order to the ADCH19 input, A (GPIO84) and B (GPIO87) pins have to be 00 for phase R, 01 for phase S, and for phase T 10.

For debugging, I added two discrete pulse generators connected to mentioned GPIO's and some selecting signals to have the visualization phases in order:

The ADC is triggered by software, but at I cannot obtain any output waveforms at all.

I made a simple setup to confirm if my SCI was working corectly:

Obtaining a clean sinusoidal waveform.

Could you please tell me what I'm doing wrong? or there is a better way to obtain these waveforms from the IC MUX as mentioned?

Thank you.