Ubuntu Networking :: Port Not Opening On Wired Connection, Fine On Wireless?

I'm fairly sure that this is an Ubuntu issue, as I've tried this on my windows computer with success.I'm running a minecraft server on my laptop, previously over a wireless connection but the data rates were too slow. On a wired connection, however, the server starts up and runs like normal but the port is not open when accessing from the network's public IP. I tested this with canyouseeme(.)org. I can get to it from other computers within the network by using a local IP, which to me seems a little strange as it seems to indicate that the port is open on the PC but somewhere in the router it gets confused due to being wired(?). Obviously I've forwarded the ports on the router (BTHomehub 2.0) with both TCP and UCP (it worked over wireless!). Any suggestions as to what might be causing this? I'm stumped.