Droid Exchange Corporate Contacts not synchronizing correctly

Hello - we have a user who is using a Droid Ultra phone to send email and maintain contacts thru his Exchange Outlook account, using the "Corporate" account application on the phone.  We have other users doing the same thing, and they do not seem to have issues with their contacts not syncing properly.  But what this user experiences, is seemingly randomly, a contact that was added in Outlook does not show up on the phone, and vice versa.  Also - there was a contact on the phone that disappeared AFTER removing the corporate account, and re-adding.  Is there anyone out there who's experienced this similar type of thing?

Thanks for your help.