SuiteCRM outlook plugin can't find archive contacts

We’ve installed SuiteCRM and installed the plugin in our Outlook express. Everything worked fine up until a few weeks ago when the Archive to SuiteCRM no longer finds any contacts. We’ve tried installing the plugin again and re-installing SuiteCRM but it still does not find the contacts. When we test the login we get a success message so the link between SuiteCRM and the plugin appears to be valid.

Any help on this will be appreciated!