I see from this thread that you are working on the root problem as to why people are getting the message "No network test servers are available". I just joined up today and am getting that message as well as "Check your network! Your network changes packets port-numbers. This may block receiving real-time UDP packet traffic from the Internet".
I'm running JamKazam Build 1.20 - "1.0.3640" on a MacBook Pro mid 2018, with wired ethernet to Apple AirPort router with NATPMP turned on, with a static public IP on the WAN side, with high speed internet 90/90.
If there is anything i can do to help test something, please let me know. I'm a systems, software, network engineer as well as play the bass in a band.
And by the way, thanks for this awesome platform. Going on 4 weeks of not jamming with my band and i'm jonesing bad. Look forward to seeing this work... i know you can solve it. As one of my mentors in tech said when i was a wee lad "It will yield to analysis." Just keep repeating it and take a deep breath. All these people complaining are just eager to use such a wonderful system, and are stuck inside.
Peace,
backinterrapin