FullTextScore not working with Cosmos DB (NoSQL)

I’m using Cosmos DB with both Full-Text & Hybrid Search for NoSQL API and Vector Search for NoSQL API (both enabled before container creation). I’ve set up the appropriate indexing policy with full-text and vector indexes.

Here are three queries I’m testing:

This full-text filter query works fine:

SELECT TOP 10 * FROM c WHERE FullTextContains(c.description, 'blah blah blah') 

This vector-only query also works (I'm calling this from a function app where im getting the embeddings etc)

SELECT TOP 10 VALUE c.reportTitle
FROM c
ORDER BY VectorDistance(c.embedding, @embedding)

❌ This fails with an error:

SELECT TOP 10 VALUE c.description
FROM c
ORDER BY RANK FullTextScore(c.description, ['allocation'])

Error message:

payload must exist nested within the outer payload field

Expected Behaviour:

According to the docs and my understanding, I should be able to use FullTextScore in combination with ORDER BY RANK for scoring. My end goal is to support hybrid search, combining both VectorDistance and FullTextScore (this also isnt working but one step at a time)

Current Setup:

My indexing policy includes:

{
  "indexingMode": "consistent",
  "automatic": true,
  "includedPaths": [{ "path": "/*" }],
  "excludedPaths": [
    { "path": "/\"_etag\"/?" },
    { "path": "/embedding/*" }
  ],
  "fullTextIndexes": [
    { "path": "/title" },
    { "path": "/description" },
    { "path": "/menu" },
    { "path": "/subMenu" }
  ],
  "vectorIndexes": [
    {
      "path": "/embedding",
      "type": "diskANN",
      "quantizationByteSize": 96,
      "indexingSearchListSize": 100
    }
  ]
}

Why does FullTextScore throw this payload error?
i get this erro both by the sqk and directly inside azure when i click "new query"

Would appreciate any help! I’m trying to combine full-text and vector search in a hybrid scoring model but am blocked here.

Thanks!