n3

A quick how to guide on what I did to make it work:

Plug in the USB-C to the side of the O4 unit.
Add battery power to drone.
Set external hairdryer on cool and blow it in the drone.
Open DJI Assistant 2.
  Register the O4 unit.
  Reboot / reopen the application.
  Upgrade firmware.
  Reboot.
Unplug USB-C from O4.

Plug USB-C into adapter for PAVO unit.
Open Betaflight.
  Save all PAVO20 settings and config in Betaflight:
    CLI tab.
      Dump all.
      Save the file.
  Clear history tab.
    Diff all.
    Save the file.
  Disconnect and then reopen Betaflight.
PORTS tab:
  USB VCP — Configuration/MSP is on.
  UART4 — Configuration/MSP is on.
  UART5 — Serial RX is on.
  All others are off.

Turn on Goggles 3.
  Hold power button.
    Starts beeping — you can pair it.
Turn on PAVO20.
  Press Bind button on the O4 unit.

Once it is connected you will see video. To get the controller to work:
Settings → Control → Remote Control → Calibrate
Settings → Control → Protocol → SBUS Baud Fast
  Auto Low Power State of Air unit — Turn on

To get the GEPRC to work again, undo these two:
Settings → Control → Protocol → SBUS Baud Fast
  Auto Low Power State of Air unit — Turn on