Answer
If this happens on a report whose projection and permission-set grants have already been double-checked and match other, working Quick Reports, consider that this can be an underlying Oracle database-level bug rather than anything wrong with the report or its configuration — at least one confirmed case was resolved only after applying a specific Oracle patch update, with IFS Support separately confirming other customers hit the same underlying Oracle issue; if standard report/permission troubleshooting turns up nothing, raising it with IFS Support to check for a known Oracle-level cause is a reasonable next step rather than continuing to re-check the report's own configuration.