Azure AD Driver 5.1.7.0300 not creating UserMailbox

We are experiencing an issue with the Azure AD Driver version 5.1.7.0300, where it is not creating User Mailboxes as expected. The users are visible in the tenant, but their mailboxes are not being provisioned correctly. We noticed that the Exchange Online service logs do not show the "New-Mailbox" command being executed. Any insights or solutions to resolve this would be appreciated. Thanks in advance.

Identity Manager Version 4.8.4