**IF YOU ARE HAVING THE SAME PROBLEM, CHECK IF THE ISP HAS ENABLED CGNAT IN YOUR SERVICE. THAT IS WHAT HAD HAPPENED WITH ME**
I just don't know what happened. Yesterday the server was perfect. BUt now, when my public IP changed (I have a DNS), my server got lan only. I was not able to connect to my server by its public ip nor dns. But the server appeared in LAN section. Please help me. I don't know what happened! Ports are working and are correct. Server is not firewalled!