Update: In a new statement, Capcom told USgamer: "The dev team has identified the problem and is working closely with the team at Microsoft to test and then deploy a patch to address the matchmaking as soon as possible. In the meantime, Online Sessions are still functional and hunters can join each other for multiplayer using the "Session ID," "Invite a Friend" and the Xbox LFG."
So it sounds like a patch is incoming for the Xbox One version of Monster Hunter: World and pretty soon too. Hopefully the patch will fix whatever issues are plaguing online matchmaking for the game on Xbox.
Original Story: Monster Hunter: World is a game best experienced online with friends. Unfortunately then for Xbox One players, there currently appears to be issues with online matchmaking for the game on that platform.
Capcom acknowledged the issue on Twitter yesterday, telling players that the company is "actively investigating" matchmaking issues on the Xbox One, and is currently working on a solution. The problems with online functionality extends to Filter Search, Squad Session Search, and Response to SOS features as well.
Hunters on Xbox One, the “Matchmake”, “Filter Search”, “Squad Session Search” and “Response to SOS” functions are currently unavailable; our dev team is currently working on a solution and we’ll provide an update as soon as it is available.— Monster Hunter (@monsterhunter) January 29, 2018
In the meantime, Capcom recommends using Session ID, friend invites, or Xbox LFG to get around matchmaking difficulties and still play with friends online.
When players first log in to Monster Hunter: World, they have the option to join or create a server to invite players in to go on hunts together. While online play is still possible on the Xbox, it's without the help of the seamless online experience on the PlayStation 4 (though PSN server outages are sabotaging online functions on the PS4 as well).
Forums like ResetEra and Reddit were full of discussions about the matchmaking problem as well. However, there appears to be a consensus among internet commenters that this whole thing could have been avoided if there was a beta for the Xbox One version of Monster Hunter: World, like there was for the PlayStation 4 last December.
Our review for Monster Hunter: World highlighted the online component of the game in our perfect score review. For more info on how online matchmaking works, check out our complete guides for the game.