So it looks like somehow this problem is at the MAVLink layer…
There should be a MAVLink message “OPTICAL_FLOW_RAD” at 1 Hz in normal mode but I don’t see this in the QGC MAVLink Inspector or Analyze widgets.
SDLOG2 does seem to save what looks like reasonable data to the SD card.
I’m having the same problem when after i successfully updated the firmware onto the px4flow, then QGC said that it fail to create a COM Port to connect the px4flow.