Hi, Did you fiugure it out? I have the same issue. Users connecting from the internet have this issue for the last couple of days. It was working fine for a few days. From within my network I can connect.
Hello, I had the same problem. Firstly, check your firewall. Port that your server uses has to be allowed. Secondly, check server.properties. Key server-ip has to be empty. Thirdly, check your tunnel’s settings. Your local address has to be 127.0.0.1 and local port has to match yours (that you have written in server.properties.
I have just solved this problem by creating a new Minecraft Java tunnel on playit.gg, then the problem has gone! Good luck!
UPD: In tunnel’s settings you can see Data center cell. Restart your playit.gg client (agent) to get a new data center or create a new tunnel.