Why have Expenditure Item and Unprocessed Cost DFFs Stopped Importing using ADFDi

Summary:  Expenditure Item and Unprocessed Cost DFFs Stopped Importing using ADFDi, but it was working over a month ago.

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I setup DFFs for Miscellaneous Transactions that use our GL LOVs (both expenditure Item DFF and Unprocessed Transaction DFFs). Using ADFDi I was able to fill in the values in the "Project Cost User Defined Attribute" fields and import. It was all working great. I tested this for about a month. I tested last week and it stopped working. None of the DFFs are importing from the ADFDi - I can create a transaction in to system form and enter the fields, but nothing comes in from the spreadsheet. Can anyone tell me why this stopped working?