Randomly lost connection to my Minecraft server, can't rejoin
Recently, I made a Minecraft server to play with my friends on. I'm hosting it off an old laptop and playing it from my PC. I have port forwarded my router and I'm using NoIP as a hostname for my friends to join through, and I connect through my public IP (which I get through searching "my ip" on google on the laptop). At first, there were no issues and I played for about an hour with friends before I got randomly disconnected to the multiplayer screen with no error.
I could no longer ping my server and it would look like this
I got this error when joining 
My friends stayed connected however I couldn't regain connection so we decided to leave it. I made a post on this forum however about 2 hours later, I checked again and I could play fine, so I removed the post. I played for a bit longer then went offline and there were no more issues. I tried logging on this morning but only to get this issue again.
I tried:
- refreshing the multiplayer menu
- restarting Minecraft
- relogging my Minecraft account
- restarting the server from my laptop
- restarting my PC
- restarting my laptop
- allowing Java and the Minecraft launcher access through the firewall
- checked the ports (25565 is open)
- connecting through "
myip", "myip:25565", the NoIP hostname, "localhost" and "localhost:25565" (none worked, and obviously localhost wouldn't)
I can play other Multiplayer servers (such as Hypixel, Manacube etc) but I just can't connect to my server whereas my friends can. I'm not sure why this is the case, any help would be appreciated!
If the Server and the Client applications are connected to the same physical network (wired and / or wirelessly) it is best to attempt to connect using the local IP and not your external IP address. (Please note that firewall rules may need to be considered to incorporate the external & internal connections).
Connecting to a device that is internal to your network using your external IP can sometimes result in NAT issues, this can be for a few reasons and is off topic for this stack exchange channel. (Google "NAT Loopback" for further information on the topic.)
This means that the server failed to reply to the query. This means, in general, that the port is incorrect, the server-ip in server.properties is set, or that the server may be using all of your wifi speed, leaving none for your computer to connect. Ensure the port is correct, and you could also try deleting the server.properties file to ensure something was not set incorrectly.