I had 3.3 running and all was good, so I thought why not place 3.5 on a different MicroSD and swap them out.
This is where my thinking may be out.
The Pi was registered and working, Flightaware would not be troubled with the swapped out card as long as it’s the same physical Pi.
The 3.5 was showing traffic on locally 8080 but Flightaware did not seem to hear it.
What was my schoolboy error?
TIA