USB-C docking bar only charging, not working as USB hub

Describe your issue

I recently replaced the motherboard on my PinePhone with a new 3GiB model to test convergence mode, and flashed the ANX7688 firmware as per these instructions: https://xnux.eu/devices/feature/anx7688.html.

When I plug the PinePhone USB-C docking bar into the phone, it charges, but does not function as a USB hub so the keyboard, trackball, and HDMI monitor are detected.

Expected Behavior

I expect Phosh to detect the docking bar as a USB hub, and enable the keyboard, trackball, and HDMI monitor.

Observed Behavior

The device charges. In dmesg:

[  121.402949] anx7688 1-0028: data role change requested to ufp

How reproducible is the bug?

Every time.

Steps to reproduce the bug

1. connect USB-C docking bar to the Pinephone
2. observe that no peripherals are detected
3. open a terminal, run dmesg, observe the message above.

What device are you using?

Which mobian repository are you using?

http://repo.mobian-project.org/bullseye

How did you get your Mobian Image?

I'm running the mobian-pinephone-phosh-20210502.img nightly from https://images.mobian-project.org/pinephone/nightly/.

Solutions you have tried

1. weeping
2. drinking copiously
3. re-flashing the nightly image to the SD card, and re-testing with a vanilla Mobian installation