What is an Xactus report, and why doesn't it match my credit bureau reports?

My lender just sent over the results of a soft pull, in the form of a report from a company called Xactus. It's reporting multiple open accounts that have since been closed, past due balances for accounts that are current, and a late payment for a student loan account that I was able to resolve with the lender. I pulled all three credit bureaus and they're squeaky clean. This is incredibly frustrating, thinking I have to go to battle with a third party when I have official documentation in hand that shows their report is wrong.

Is this the report used by the underwriters, or do they pull the credit bureau reports directly?