Records not getting imported except one

Hello Experts,

We are facing an import issue. We import the data to MDM in XML format via MDIS. The issue we are facing is : when we try to import a file(with 5 records) which has matching rule as Remote key, when the matching status is Single exact, 5 records should be created in MDM system, but whereas four records are getting skipped and only the 5th record gets created in MDM system. If we delete the 5th record and process again, the fourth record which was 2nd last earlier gets created but the rest of the records are getting skipped.

Can any one let me know how to solve this issue?

Thanks

Vinoth