Enable DB Query events in tracer and trace the RD in both production and lower environment. The DB Query event will contain both the query and the prepared values. If no difference is found, then substitute the prepared values into the query and run the prepared query directly against the databases. See if the results are the same, and proceed from there.
Some things to check for specifically:
Does the function alias use another OOTB database function that is defined in the lower environment DB and not in production?
Is the invoice completion date time column populated and exposed properly in production?