Re: Two players on the same connection cannot play at the same time.

Hey @Perplexinn connection issues such as this are common when you have multiple consoles or PC on the same network attempting to play together

Can you try the following to see if it helps: 

• Log into your modem / router
• Turn OFF UPNP.
• Turn off PC UPnP Service:
• Press: Windows-button a window should pop up. Write: “services.msc” (without the “) then press enter.
• In the list of services, scroll down to “UPnP Device Host”, click it and press “Stop service”. Now do the same thing but with the service “SSDP Discovery”.
• Exit the window and go to control panel-> Network and Internet-> Network and Sharing Centre-> Change advanced sharing settings (to the left)-> Under “network discovery” select to turn off network discovery
• Save your changes

Let me know how you get on.

Darko