Multitenant Collaboration Sync Paused

During the re-initiation of initial synchronization of Multitenant Collaboration, syncing is paused with the error message below.

Code: Forbidden, Message: Invitations are blocked for this directory due to suspicious activity. Please contact Microsoft support for help.

Opened a ticket via Microsoft 365 Admin Center but still got no agent/response.

Does anyone have a clue on how to resolve this issue?