Users keep having to log in when opening Outlook

Please try to locate the issue by below:

1. Enable Shared Computer Activation (SCA)

• Ensure that Shared Computer Activation is enabled for Microsoft 365 apps. This is crucial for multi-user environments like AVD.
• You can enable it via Group Policy or by setting the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\ClickToRun\Configuration
SharedComputerLicensing = 1

2. Check FSLogix Profile Configuration

• Verify that FSLogix is correctly configured to roam all necessary Outlook data, including credentials and settings.
• Ensure that the ProfileType is set to VHD or VHDX and that the profile container is properly mounted during login.
• Check the redirections.xml file to ensure that no critical Outlook folders (e.g., %LocalAppData%\Microsoft\Outlook) are excluded from roaming.

3. Enable Modern Authentication

• Confirm that Modern Authentication is enabled for your Microsoft 365 tenant. This ensures seamless single sign-on (SSO) for users with multiple accounts.
• You can check this in the Microsoft 365 Admin Center under Settings > Org Settings > Modern Authentication.

4. Credential Manager Cleanup

• Sometimes, cached credentials in the Windows Credential Manager can cause conflicts. Clear any old or duplicate credentials related to Outlook or Microsoft 365.

5. Adjust Outlook Startup Behavior

• Since the issue occurs when Outlook is opened first, consider setting a policy to delay Outlook startup until other Microsoft 365 apps (like Word or Excel) have initialized. This can help ensure the correct account is authenticated.

6. Update FSLogix and AVD Components

• Ensure that you are using the latest versions of FSLogix and AVD components. Microsoft frequently releases updates to address compatibility and performance issues.