The SEP (Symantec Endpoint Security) or SES (Symantec Endpoint Security) Agent may interfere with the Microsoft Teams app, and it can prevent the application from starting correctly.
To prevent SEP/SES from interfere with Microsoft Teams, Add the following Exclusions
Wild card (*) is not supported. We recommend to use the Prefix variable [USER_PROFILE] which will correspond to all the users.
Examples:
On-Prem SEPM
SES-ICDM
Configuring Exceptions policies in Endpoint Protection Manager
https://knowledge.broadcom.com/external/article?articleId=156028
How to include or exclude Teams from antivirus or DLP applications
https://docs.microsoft.com/en-us/microsoftteams/troubleshoot/teams-administration/include-exclude-teams-from-antivirus-dlp