That's right pontiend, 30002 is what I'm always using with the ddns ip out to you and the others.
30003 is the Basestation port I'm using from Flight Radar to me from my RPi.
During this present problem, the RPi is continuing behaving itself feeding my aircraft to the Flight Radar site, so it seems to be a glitch with VRS.
I've also separately installed VRS on a laptop, but still no go.