New user unable to search for external contacts

Hi jonragnar , If a specific user in your organization is unable to perform external lookups of users in Teams while others can, there could be a few potential reasons for this issue. Here are some steps you can take to troubleshoot the problem:

1. Check external access settings: Verify that external access is enabled for the user who is experiencing the issue. External access allows users to communicate and collaborate with external users outside of your organization. You can check and configure this setting in the Microsoft Teams admin center or by using PowerShell commands.

2. Verify user's contact settings: Ensure that the user's contact settings are properly configured to allow external lookups. In Teams, users can control their contact settings to determine who can find and communicate with them. Make sure that the user hasn't accidentally restricted external users from finding them.

3. Review user's privacy settings: Check the user's privacy settings in Microsoft 365 to ensure that they haven't enabled any settings that might restrict external lookups. In the Microsoft 365 admin center, navigate to the user's account settings and review the privacy options.

4. Confirm network connectivity: Ensure that the user's network connection is stable and not experiencing any issues. A poor network connection could potentially interfere with external lookups in Teams.

5. Clear Teams cache: Sometimes, cache files in Teams can cause unexpected behavior. Instruct the user to clear the Teams cache by clicking on their profile picture in the Teams desktop app, selecting "Settings," and then choosing "Clear Cache."

6. Try on a different device: Ask the user to test external lookups on a different device or using the Teams web app. This can help determine if the issue is specific to the user's device or client.

7. Contact Microsoft support: If the issue persists after trying the above steps, it's recommended to reach out to Microsoft Support for further assistance. They can investigate the issue more deeply and provide specific guidance based on your organization's configuration.

By following these troubleshooting steps, you should be able to identify and resolve the issue with the user's inability to perform external lookups in Teams.