Did you applly any Sensitivity label to this group? Try removing it:
- Sign in to the Azure AD admin center with a Global admin or Groups admin account, or as a group owner.
- Select Groups.
- From the All groups page, select the group that you want to remove the label from.
- On the Group page, select Properties.
- Select Remove.
- Select Save to apply your changes.
If it's still not fixed, contact M365 support:
If an Answer is helpful, please click "Accept Answer" and upvote it.
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.