To resolve the issue of a SCIM User not showing within a SCIM Group, you can Restart Provisioning within your Azure AD; this will restart the provisioning service for all Users and Groups as well as remove any watermarks.
The process can take some time, so please allow 24 hours before checking back on the Group.
The users should subsequently appear within the Group as expected. If this is not the case, please contact our Support team at support@metacompliance.com.