I have recently created a minecraft java 1.15.2 server. it took some time to set up but i think i did everything i was supposed to. I port forwarded on port 25565, allowed accesses through my firewall, and i gave my friends my ipv4 public IP address. they were all able to join just fine. but the next day when they wanted to join nobody could. but when i got on a different computer that was connected to my mobile hotspot it allowed me to connect, but only once. i disconnected and 30 seconds later when i tried to join it gave me this error "io.netty.channel.AbstractChannel$AnnotatedConnectedException: connection timed out: no further information:" I've tried reinstalling the server software, I made sure my IP address is static but nothing has worked. I am still able to join on my local network so i think it has something to do with the port but I'm not sure what.