Accessing and using Microsoft Teams on smartphones and tablets across platforms
The Microsoft Teams Shifts "Specific Date Availability" blank screen bug is directly tied to the global Exchange Web Services (EWS) deprecation that began on October 1, 2026.
Despite frontline tier-1 support denying the issue, this has been confirmed as a widespread bug affecting organizations globally following the rollout of the EWS phased shutdown. On October 1, 2026, Microsoft officially began blocking default EWS requests and shifted calendar availability lookups over to the Microsoft Graph API. This infrastructure change broke the mobile workflow for adding specific dates in Shifts, causing the app to return a blank page when users hit "+ Add Availability".
The following steps outline why this is happening and how to force your support ticket past Microsoft’s initial denials:
Why the EWS Change Broke Shifts
• The EWSEnabled=Null Flip: On October 1, 2026, Microsoft automatically flipped the backend EWSEnabled parameter from Null to False for tenants. Because legacy Teams Shifts architecture still relied on EWS for certain calendar data syncs, the communication line dropped.
You can then just re-enable EWS by setting EWSEnabled to back Null after it was automatically set to False by Microsoft (after October 1st). Need to change this using PowerShell. There will be a brief service interruption while the change takes effect, but re-enablement remains available until April 1st, 2027.
ANYBODY TRIED THIS AS FIX???