Arris: can not host a game NAT Type : Strict

Check your nat type at the bottom before starting a match. If it is moderate or strict there is your problem. When it is on moderate Or strict and you go to migrate to a new host then you can have issue connecting to the new host depending on your nat
type and the host nat type. Let me know if this is your issue and I can help you with getting your nat type back to open.

Did you try changing your NAT type? The helpdoc says:

Open:

With an OPEN NAT type, you’re able to chat with other people, as well as

join and host multiplayer games with people who have any NAT type on

their network

Moderate:
With a MODERATE NAT type, you’re able to chat and play multiplayer games

with some people; however, you might not be able to hear or play with

others, and normally you won’t be chosen as the host of a match.

Strict:

With a STRICT NAT type, you’re only able to chat and play multiplayer

games with people who have an OPEN NAT type. You can’t be chosen as the

host of a match.

-- So I take that to mean if you have STRICT NAT, and if anyone in the group DOES NOT have an OPEN NAT type you are going to have problems.

Are you both running STRICT NAT type?

Sounds like it might be a NAT issue

OPEN NAT MODERATE NAT STRICT NAT

With an OPEN NAT type, you’re able to chat with other people, as well as join and host multiplayer games with people who have any NAT type on their network.

With a MODERATE NAT type, you’re able to chat and play multiplayer games with some people; however, you might not be able to hear or play with others, and normally you won’t be chosen as the host of a match.

With a STRICT NAT type, you’re only able to chat and play multiplayer games with people who have an OPEN NAT type. You can’t be chosen as the host of a match.

Check this link for a possible solution:
https://support.xbox.com/en-US/xbox-one/networking/nat-error-solution

If you can't find it contact your ISP

I would check NAT types. Sometimes if you both have strict or even moderate NAT types it can cause issues when one of you is the host.

If you can get the NAT types open, it solves a lot of issues like these. Another workaround is to use a game with a dedicated 3rd party host (which minecraft has in the form of Realms if the subscription is worth it to you)