Ubuntu 16.04 runs the game server software written in PHP 7. But the problem is not in the software, but in the system. The game client cannot connect to the server. There is no information in the server logs that they are trying to connect to it, and the client cannot receive a response from the server. However, this problem is solved for some time in a very strange way. It is necessary to go to the apache web server, which is running on the same VPS, so the client immediately connects to the server. This circumstance makes me think that the problem is with the network settings of the system.
Server software - PocketMine, launched on port 19131. The port was opened using sudo ufw allow 19131 . The netstat output is as follows:
Has anyone come across this when the connection is possible only after entering the site in the browser? How can these actions be related?
