Two People At same House One Disconnecting

Games Halo 5: Guardians
1

I can Play with anyone and by myself fine. As soon as I play with my brother on the Same Router sometimes it will kick one of us from the game.

This gets very annoying. I have a R7000 Gaming Netgear Router. Never Had any Network issues with Halo MCC or any other game.
Sometimes Hard Resetting both consoles lets us playa few games without issues.
Sometimes that doesn’t work.

Resetting the whole router fixes it for a few games but this is a constant issue.

I narrowed it down to Dedicated server issues.
Me and my brother cant even start a custom game up with just us two when having this issue.

PLEASE FIX or TELL ME WHAT PORTS TO OPEN.

because we can play alone without each other as much as we want. but cant play together.

2

Try connecting one console directly to the modem, the Xbox One doesn’t play well when having multiple on a single gateway/router unless you have a multi NAT capable router and or gateway

3

Here is a blog post with some steps that might help resolve the issue. How to use multiple xbox one consoles in a network – A Geeks World