Wrong result: `GROUP_CONCAT`/`JSON_ARRAYAGG` returns 0 rows when a materialized derived table containing a BLOB-family column is accessed via `derived_with_keys` (`ref=const`)

We had an issue using JSON_ARRAYAGG on top a multi-table derived containting several CTEs exposing JSON fields.

The same query without the function returned rows, even with grouping. When adding the aggregation it silently fails resulting an empty set.

You'll find all informations in MD file attached.
It's AI generated, but human tested.

We noticed the bug while testing a view to be implemented, so it's not found by AI.