For some reason party took too long to start

Hi there, Could you check your NAT type and get back to us on here with your findings? It also might be a good idea to ask your friends what their NAT type is as loss of connection or problems with connecting can manifest from either end.

Right, I've checked my NAT type on my console and it says that "your network is behind a firewall(or not connected). I hadn't realized that I can't play multiplayer aswell, until yesterday. When I check my multiplayer connection it says it can't get a Teredo
IP address. I've tried enabling and disabling UPnP but the same message still appears. My friend's NAT types are all open.

I've plugged it in the wall, I've opened ports, could it be DNS? Whatever that may be..

DNS would be the tech equivalent of the Phone operator in the old days....basically, it helps connect you with the website you happen to be trying to access. Some DNS servers are better than others to their larger size enabling them to handle more DNS requests. For those having DNS issues (or network issues or undetermined causes), it's always worth manually changing the DNS in Network settings to that of Google, Cloudflare or any other one.

Try Cloudflare first 1.1.1.1

The Google 8.8.8.8

You can try this: The first step in resetting an Xbox One is to open the main menu. This can be accomplished in one of two ways:

Press the home button on your Xbox One controller. This is the illuminated button with a stylized X that is centrally located on the front of the controller near the top.

Alternately, you can press the left bumper until you reach the home tab, and then press left on the d-pad.

Press down on the d-pad until you reach the gear icon.

Press the A button to select the gear icon.

With all settings highlighted, press the A button again to open the settings menu.

Press down on the d-pad until you reach System.

Press the A button to open the ​System submenu.

With console info highlighted, press the A button again.

Press down on the d-pad to select reset console.

Press the A button to select this option and move to the final step.

Press left on the d-pad to select Reset and keep my games & apps. Then press the A button. This is the less thorough of the two options, as it only resets the Xbox One firmware and settings without touching your games and apps. Try this first, as it allows you to avoid downloading everything all over again.

YOU WILL NEED YOUR EMAIL AND PASSWORD

After some intensive googling I think I did it

Yet no luck.

The bandwidth usage won't go over 1mbps.

Which is weird, because it is downloading games, but then they won't open.

I've plugged it in the wall, I've opened ports, could it be DNS? Whatever that may be..