I connected my HFN with that cable to my Octo (Flow connector) and my flow rate reading from HFN disappeared and what I got on Octo was wildly different.
Without the cable, for some reason Octo isnt able to get the flow rate on its sensor (I had assumed it would get it from the software side of things automatically, but it looks like its only able to read from the connector)
Read the 3 posts prior to yours and see if that helps.
Edit: If you have both HFN & octo on usb, you can import the flow rate from the HFN to a Soft. Sensor on the octo, and the flow rate will be available to the octo.