"Teredo is unable to qualify", "server connectivty is blocked", can't play multiplayer games

Alright, so I've been trying to get into my friend's java Minecraft server, but the same error pops up every time: "Failed to connect to server io.netty.channel.Abstract.channel$AnnotatedConnectException: Connection refused: no further information."

So, then I went to check on the "gaming" category in my settings, and went to xbox networking. When I checked the connection, the NAT type said: "Teredo is unable to qualify", and the server connectivity said "blocked". It also said "This could block you
from playing multiplayer games", which was true.

After that, I clicked "fix it" then "check again" then restarted my computer and nothing changed. I then clicked on a link that said "click here for more information" and it took me to xbox support. There were 13 different solutions that were on the page,
and none of them did anything to help me. I also tried resetting my router and that didn't work either.

I actually had this same problem on my laptop. I would try to connect to my friend's server on java, and the same error code would pop up. At first, I thought there was something wrong with the laptop or the game itself, but when the same problem came up
on my pc, I knew that it was a lot more serious than that. I'm thinking that it has something to do with my Wifi or internet connection but I'm not really sure. I just want to fix it.

:)