Answer
This has been confirmed as an Aurena-specific bug in how it handles Query-Builder-generated data sources, as opposed to SQL-based ones built on the identical underlying view. The practical workaround is to rebuild the affected Lobby element's data source using SQL directly instead of the Query Builder tool — a SQL-based data source against the same view works correctly in both Enterprise Explorer and Aurena, where the Query-Builder-based equivalent doesn't. If you hit this, also raise a support case with IFS, since it's a genuine platform bug rather than something fixable purely through Lobby configuration.