Users can’t access SharePoint Online sites and receive an authentication error

Title: Users can’t access SharePoint Online sites and receive an authentication error
User impact: Users may be unable to access SharePoint Online sites and receive an authentication error.
Current status: According to our monitoring telemetry, the issue is now remediated for the majority of users; however, a subset of users are still experiencing impact. To ensure that the problem is comprehensively addressed, we’re deploying a secondary fix, and we anticipate being able to outline an estimated time to resolution in our next scheduled update.
Scope of impact: Your organization is affected by this event, and some users attempting to access SharePoint Online sites may be impacted.
Start time: Wednesday, February 7, 2024, at 1:00 AM UTC
Root cause: A recent update intended to optimize the code path leveraged for users’ sign-ins introduced a code issue, resulting in impact.
Next update by: Sunday, February 11, 2024, at 2:30 AM UTC