401 Unauthorized error in MS Teams

When a news post is published in our intranet in Sharepoint, a MS Teams notification is sent from the system to all colleagues who are used to collaborating (they are in his “circles” according to VIVA Insights) with the author of the post.
Although the publication is successful and the link to the news post is active, sometimes those who click on the notification from MS Teams receive a “401 Unauthorized” error message that makes the post unviewable from MS Teams.

In the past we fixed this issue on the specific client by clearing the Teams cache, but we have more than 6000 clients...
This creates a flaw in the user experience that we need to fix. Thanks!