If the Payment Txn Status is on Matching Start Status, then check:

1. On the Merchant Facility related to the Payment Txn, check the picklist Field "Automatic Matching".  If this is set to  blank, "Match Only" or "Do Not Match" then the status is stay at Matching Start and will await for your admin user to go through the Manual Matching Process
2. Check the "Error Log - Payments2Us" for any errors.