Content Understanding (2025-11-01): Knowledge labelled samples ignored, even on the labelled document

We use Azure Content Understanding (GA API 2025-11-01) with a custom document analyzer (baseAnalyzerId prebuilt-document, models gpt-5.2 and text-embedding-3-large) to extract data from purchase order acknowledgements received from our suppliers. We added a labelled sample in Content Understanding Studio, but the corrected labels have no effect, even when analysing the exact document that was labelled.

What we tested (same 3-page document):

1. Line-level UnitPrice (method extract): corrected on all 5-line items to the printed net unit prices. The analyzer still returns the original (pre-discount) prices.
2. Diagnostic test on a header field: SupplierOrderNumber (method extract, top-level, not nested) was deliberately corrected to a different value that is clearly printed and labelled on the page. The analyzer still returns the original value.

What we already ruled out:

• Analyzer was rebuilt after labeling (and recreated from scratch).
• All affected fields use extract; also tested with no generate fields at all.
• Not OCR: the labeled values are read correctly in the result markdown.
• Label files are saved as "corrected", active, and in the analyzer's knowledgeSources folder.
• Storage access is fine (managed identity has Blob Data Contributor; network open to all).
• Analyzer is "ready" with no warnings; embedding tokens show retrieval runs.

Questions:

1. Is there anything else required for labelled samples to take effect in the GA API that we may be missing?
2. Is there a way to verify which labelled samples were retrieved and applied during a specific analysis?
3. Is this a known issue, and would the 2026-06-01-preview training approach behave differently?

We can share the analyzer definition, label files and analyze response (with operation ID) privately if needed.