AD5253 Dual Supply Setup

I was hoping to get some help setting up the AD5253 in a Dual Supply configuration.

It tested successfully using single supply setup (5V), but in order to control a negative output (COONN15A:  0-> -2V), I need to use the dual supply setup.

When I use the below setup, I can connect successfully to my script, yet when I run the command to control the wiper taps (also below), I receive an I2C error. I realize that without the full script you will not be able to fully understand why the I2C error appears, but I was hoping that you could look over the setup I have used below and advise me on whether I have made a mistake.

This is the Setup that I have used:

Thank you very much,

Twahidi

The specific function to control resistance:

*********************************************************  
def setResistance(self, value: int = 63):
    #    self.getCurrentAndVoltage()          
    bytes_out = int(value)                           // User inputs tap value from 0-63 for full range of 50K resistor
    self.i2cWrite(0x5A, [0x00, bytes_out])           // AD1 SET LOW, AD0 SET HIGH
   
    resWA = ((64 - bytes_out) / 64) * 50000 + 75     
    return (resWA)                                   // Prints out expected resistance

********************************************************************************

REFERENCES:

Single supply setup:

WP/AD0 -->5v on USB microchip

DGND/AD1 --> GND on USB microchip

SCL-->SCL on USB microchip

SDA -->SDA on USB microchip

Link to MC1663 Programmable Microchip Schematic (used for I2C communication):

https://ww1.microchip.com/downloads/en/DeviceDoc/MCP1663-USB-Programmable-Power-Supply-Reference-Design-Users-Guide-DS50002722A.pdf

Relative Schematic:

Custom Power Supply Negative Output subsection: 

 R36( 100K mechanical POT) being replaced by AD5253