Unable to connect to tcp port

[tom93]

This sounds similar to my issue, which turned out to be due to the recent release of shared IPs:

[Outage?] "Connection reset by peer" when using non-default ports

By default, we allocate a shared IP address on Nomad platform, which only supports HTTP/S on 80/443. Running flyctl ips allocate-v4, as you did with Machines, will set you up with a dedicated IP which you can use custom ports with. (Do note we will start charging $2/mo for dedicated IPs in January.)