Ran into this with one of our reports too and asked AI to review it (below) and sure enough null date fields are now showing as 01/01/1. Looks like Epicor changed how null dates are displayed.
In my case it was a BAQ report so was able to add a calculated field to overcome it and modify the SSRS report. Total unneeded PITA but 
CASE
WHEN Table.FieldName <= '0001-01-01' THEN NULL
WHEN Table.FieldName <= '1753-01-01' THEN NULL
ELSE Table.FieldName
END
AI review:
