There's a new update for Monster Hunter: World today (version 1.05 on PS4, 184.108.40.206 on Xbox One) that adds some balance changes to the game's weapons, and hopefully fixes the online multiplayer issues on both PS4 and Xbox One.
There's been some issues with Squads in Monster Hunter: World which Capcom says has been addressed in the latest update. There were times when the game would fail to load a squad telling players it was unable to retrieve squad information, and to try again. While the issue is fixed now, affected players lost their Squad data after the fix and must recreate their Squad. Additionally, a bug that let a non-Squad member join a Squad session without an invite was also squashed.
Matchmaking on the Xbox One is still currently being worked on, with Capcom stating that the "development team is also working tirelessly on pinpointing the issues with matchmaking on Xbox One. We apologize for the delay and appreciate your continued patience and support as we track down and solve these issues."
You can still play online on the Xbox One with friends in Monster Hunter: World, but through various workarounds. Either by creating online lobbies, invite a friend features, or responding to SOS calls.
As for balance updates, the patch mainly affects Slicing ammo, which has been nerfed for damage. Additionally, the maximum amount of Slashberries a player can carry has been lowered to 30.
Our complete Monster Hunter: World guide will help you quickly get started and become the best hunter you can be. But as Monster Hunter: World continues to dominate sales, there appears to be some issues, like the matchmaking on Xbox One and the HDR graphical strangeness, that still need to be ironed out.