I was just trying to migrate a Realm into a self-hosted Bedrock server, and we got port forwarding and everything working, had a friend join and test the server around. They were able to join and we were able to do things normally as in a Realm or a normal server.

Just today, it stopped working. I tried opening the server as usual, it would report "opened port 19132" in the console, netstat reports it's listening to port 19132, but when I use telnet or the ping.eu website to test the port, both reports the port is closed.

Connecting to the server using the same machine works normally, but my friends are unable to connect. I have no idea what happened, as I do not ever recall making any change between when it was working and when it was not.