Digital Potentiometer Not Working

I am trying to control an AD5206 digital potentiometer on a PocketBeagle (smaller Beaglebone Black essentially). I have an entry in my device tree for spidev, and I know the SPI pins are working because I can talk to a different chip on the bus (an MCP3208). I probed the CS line of the pot to make sure it was being selected during the write, which it was. However, I am measuring random resistances at the output of the pot (when measuring the resistance between DP0_B and AVCC).

Here is the relevant part of the schematic:

And the relevant code controlling it (this function gets called every two seconds in my main file):

int DigitalPotentiometer::setResistance(unsigned int channel, 
                                            unsigned int resistance) {

    // Create the 11-bit word
    unsigned int data[] = {channel, resistance};

    // Send the data over the SPI interface
    struct spi_ioc_transfer tr = {
        tx_buf        : (unsigned long)data,
        rx_buf        : (unsigned long)NULL,
        len           : 2,
        speed_hz      : 10000,
        delay_usecs   : 0,
        bits_per_word : 0
    };

    int retval = ioctl(this->_fd, SPI_IOC_MESSAGE(1), &tr);

    // Expected wiper settling time is 2us for the 10K variant, wait some extra
    usleep(5);

    return retval;
}

And the device tree file:

/dts-v1/;
/plugin/;

/ {
    compatible = "ti,am335x-pocketbeagle";
    part-number = "mm-cape";
    version = "00A0";

    fragment@0 {
        target = <&ocp>;
        __overlay__ {
            P1_08_pinmux { status = "disabled"; }; /* SCLK - spi0_sclk - P1_08 */
            P1_10_pinmux { status = "disabled"; }; /* MISO - spi0_d0   - P1_10 */
            P1_12_pinmux { status = "disabled"; }; /* MOSI - spi0_d1   - P1_12 */
            P1_35_pinmux { status = "disabled"; }; /* CS0  - lcd_pclk  - P1_35 */
            P2_02_pinmux { status = "disabled"; }; /* CS1 - gpmc_a11   - P2_02 */
            P1_06_pinmux { status = "disabled"; }; /* CS2 - spi0_cs0   - P1_06 */
            P2_19_pinmux { status = "disabled"; }; /* CS3 - gpmc_ad11  - P2_19 */
            P2_07_pinmux { status = "disabled"; }; /* CS4 - gpmc_wpn   - P2_07 */
        };
    };

    fragment@1 {
        target = <&ocp>;
        __overlay__ {
            cape-universal { status = "disabled"; };
        };
    };

    fragment@2 {
        target = <&ocp>;
        __overlay__ {
            cape-universal@1 {
                compatible = "gpio-of-helper";
                status = "okay";
                pinctrl-names = "default";
                pinctrl-0 = <>;
            };
        };
    };

    fragment@3 {
        target = <&am33xx_pinmux>;
        __overlay__ {
            spi0_pins: spi0_pins {
                pinctrl-single,pins = <
                    0x150 0x30 /* SCLK - spi0_sclk (MODE0 | INPUT  | PULLUP) */
                    0x154 0x30 /* MISO - spi0_d0   (MODE0 | INPUT  | PULLUP) */
                    0x158 0x10 /* MOSI - spi0_d1   (MODE0 | OUTPUT | PULLUP) */
                    0x0e8 0x17 /* CS0 - lcd_pclk   (MODE7 | OUTPUT | PULLUP) */
                    0x06c 0x17 /* CS1 - gpmc_a11   (MODE7 | OUTPUT | PULLUP) */
                    0x15c 0x17 /* CS2 - spi0_cs0   (MODE7 | OUTPUT | PULLUP) */
                    0x02c 0x17 /* CS3 - gpmc_ad11  (MODE7 | OUTPUT | PULLUP) */
                    0x074 0x17 /* CS4 - gpmc_wpn   (MODE7 | OUTPUT | PULLUP) */
                >;
            };
        };
    };

    fragment@4 {
        target = <&spi0>;
        __overlay__ {
            #address-cells = <1>;
            #size-cells = <0>;
            status = "okay";
            pinctrl-names = "default";
            pinctrl-0 = <&spi0_pins>;
            cs-gpios = <&gpio2 24 0>, 
                        <&gpio1 27 0>, 
                        <&gpio0 5 0>, 
                        <&gpio0 27 0>, 
                        <&gpio0 31 0>;

            channel@0 {
                status = "disabled";
            };

            channel@1 {
                status = "disabled";
            };

            adc0: mcp320x@0 {
                compatible = "microchip,mcp3208";
                reg = <0>;
                spi-max-frequency = <1000000>;
            };

            adc1: mcp320x@1 {
                compatible = "microchip,mcp3208";
                reg = <1>;
                spi-max-frequency = <1000000>;
            };

            pot0: spidev@2 {
                compatible = "spidev";
                reg = <2>;
                spi-max-frequency = <1000000>;
            };

            pot1: spidev@3 {
                compatible = "spidev";
                reg = <3>;
                spi-max-frequency = <1000000>;
            };

            pot2: spidev@4 {
                compatible = "spidev";
                reg = <4>;
                spi-max-frequency = <1000000>;
            };
        };
    };
};