Step 2) Grab your internal IP address by typing ipconfig. A guide on
Step 3) Open server.properties from your Minecraft servers folder, it is in the same location as the plugins/ folder, and your spigot.jar.
Step 4) Take the IP address from Step 2 that looks like 192.168.1.XYZ and place that on the line that says server-address=.
Restart server, test your connection via www.canyouseeme.org - if after this, you receive a failure message from canyouseeme, you need to complete your port-forwarding on your router. A guide on port forwarding can be found here.
Please post your results.
The word "localhost" is often confused with "127.0.0.1" - Technically speaking they are both Localhost, in the same way that both a Toyota and a Honda are cars. However, there are major differences. localhost - the word; often refers to a socket based connection, which is software, not networking. Whereas, 127.0.0.1, is networking, and uses a network card (so to speak). Be sure to only use the word localhost, if you're actually talking about a socketed connection, in all other, and most often, use the numbers 127.0.0.1
Additionally; specifically in Minecraft, when leaving the option "server-address" in server.properties blank, it defaults to a socketed localhost connection, and does not bind to an IP address. In the event you wish your server to connect to ANY available LAN connection, you want to fill in 0.0.0.0 (good for servers with multiple physical connections and multiple IPv4 addresses.) - In almost all circumstances, you want to manually specify which IPv4 address to connect to: ie 192.168.1.XYZ or 10.0.0.XYZ - or even your externally assigned IP address if you do not utilize NAT addressing. (If you have a home router, you're using NAT and need to look for 192./10.
I also know that it isn't the firewall or the network that's all i really know
I disagree, check on host machine to see if the computer thinks the network is public or private. by the sounds of it, the computer sees it as public, which hides it from other machines. in that case, you need to set it to private, which allows other devices on the same network to see and connect. If that doesn't work, then you may be correct. I only found this out recently and hope it helps.
PLease quote when you reply to this so that I can come back to hear results.