In the recent monthly update for Halo Infinite, it was announced that the split-screen co-op support for the game was been canceled by 343 Industries. Regarding this cancellation the studio said, "In order to improve and accelerate ongoing live service development, and to better address player feedback and quality of life updates, we have reallocated studio resources and are no longer working on local campaign split-screen co-op." However, now fans have found away to exploit a glitch to access this mode.
Splitscreen co-op is considered a staple in the Halo series and also one of the reasons the series has achieved universal popularity in gaming and wider pop culture. Being let down by the developers, fans of the series took the matter into their own hands and discovered a glitch that would help them access the split-screen co-op section of Halo Infinite. The process of this glitch was explained via a Tweet by Halo Creation, a French Halo community focusing on fan creations. As of now, the glitch still works for the Xbox Series X and S. They credited the discovery of this glitch to @Zeny_IC.
In order to play split-screen co-op, an Xbox Series X or S would be required, as well as one friend who is online in the menus. Then, the player needs to go into the campaign and load a save. While the game is loading, the player has to quickly go to the Friends list and join the online friend. Afterward, they can leave the Fireteam and create a custom offline server. Finally, they will have to connect their other controllers and profiles to start playing split-screen co-op. According to @HaloCreation, the split-screen co-op in Halo Infinite works for up to 4 players just like previous games in the series.
343 Industries has yet to make any official statement regarding this glitch. Halo Infinite will be getting its biggest update on November 8 which will include a variety of new features, maps, weapons, and more.