It's going to sound like a stupid question, but did you bind up your Tx to the Rx?
Go into the configuration menu and make sure your settings are correct in there. I'm thinking maybe it needs serial turned on or something but I have no way of knowing what uart its on or what setting it needs. should say it in the manual for the FC.
Yeah I went through all the steps and nothing. This stinks. Back to the drawing boards i guess.
You may be able to use cleanflight configurator. It's worth a shot anyway.