Xbox One Multiplayer Connection Issues

Xbox One Multiplayer Connection Issues
Hey guys,

I've been having issues with multiplayer connection on my Xbox One. We recently got a new modem/router two days ago and it hasn't allowed me to connect to COD: Warzone. Switched from Linksys to TPLink.

I can run tests, but every time I run the multiplayer connection tests, it doesn't work. Sometimes, when I run a multiplayer test, it'll knock off the wifi for like 20-30 seconds.

Test network connection is good and test network speed & statistics show this:

Download Speed: 85.18 Mbps

Upload Speed: Not Available

Packet Loss: 0%

MTU: Not Available

Latency: 30ms

Wireless Strength: 100%

There was a problem with some of the tests. Try again later.

I've reset the modem/router, reset my xbox one, set NAT Forwarding, called my ISP, and nothing has worked. I have been trying for hours. If anybody could help, that would be great.

Thanks!

:)