Update: In an email to Tom's Guide, a representative for 343 Industries has confirmed that the team is aware of the issue and is actively working on a fix.
Via posts made on the Halo Waypoint forums, as well as gaming forum resetEra (thanks IGN), some players are claiming that a bug is destroying save data in Halo Infinite, affecting both single-player and multiplayer data. This bug is occurring on both Xbox Series X and PC.
According to user 99humanity on the resetERA forums, they were on the second-to-last mission in the campaign on PC. Upon loading into the game, they were suddenly thrown into a third-person view with Master Chief clipping through the floor.
According to 99humanity, the issue could stem from a login bug that may confuse Halo Infinite. In 99humanity's case, while they were logged in, an Xbox sign-in pop up appeared saying "Let's Go." Upon clicking this prompt, it essentially double signed-in, potentially corrupting the save file.
Per 99humanity, the double login bug can happen if a user plugs in a second controller, if a controller gets disconnected, when switching from a wired controller to Bluetooth, being logged in on Xbox and then logging in on PC and using quick resume on Xbox when playing another game with multiple users signed into the same account.
A player also uploaded a video detailing his experience.
Herb_Farmer_44, a user on the Halo Waypoint forums, did submit a ticket with 343 Industries and got a response. In it, a representative said they were aware of the problem and that, "we don’t know how to fix it, and if we ever do, we’ll let you know."
Here's the text of the ticket that Herb_Farmer_44 posted:
"At this time, we don’t have a workaround and can’t predict when there might be a resolution, but your issue has been logged with our developers. They will use the information you provided during their investigation.
If this issue is resolved in an update, we will notify you. If not, your ticket may remain in an open state until a game update. We will check in with you whenever a game update is released to ensure that your issue is still occurring.
If our developers have a question for you or we discover a workaround, we may reach back out to you with questions or steps for you to try. If you discover a workaround yourself, please feel free to send it back to us! We can share that information with other players encountering the same issue and with our developers for further investigation.
Our developers look at issues which multiple people have reported so if you know others experiencing this issue, ask them to file a ticket.
Halo Agent Yoke"
A user on Reddit posted of a similar issue, and briefly there was a workaround on PC. But it seems that the solution no longer works.
Beyond what Herb_Farmer_44 posted above, 343 Industries has not acknowledged the issue in a blog post or press release. At the moment, we're not sure of if or when a solution will come through. The best we can do is wait for 343 Industries to publish release notes after its next update.