iOS 27: English sentence embedding model unavailable on physical devices

I’m seeing NLEmbedding.sentenceEmbedding(for: .english) return nil on physical devices running iOS 27, both in debug builds under Xcode and in production. The same failure has been observed across thousands of users on iOS 27.

One affected device runs iOS 27.0.1 (24A446).

Minimal example with diagnostics:

import NaturalLanguage

let language = NLLanguage.english

print("Current revision:",
      NLEmbedding.currentSentenceEmbeddingRevision(for: language))
print("Supported revisions:",
      Array(NLEmbedding.supportedSentenceEmbeddingRevisions(for: language)))

if let model = NLEmbedding.sentenceEmbedding(for: language) {
    print("Loaded revision:", model.revision,
          "dimension:", model.dimension)
} else {
    print("Sentence embedding model unavailable")
}

On affected devices, the current revision is 1 and supported revisions are [1], but model loading returns nil. The framework logs:

Unable to locate Asset for sentence embedding model for local en.

The failure occurs during model loading, before any call to vector(for:). This uses Apple’s built-in English sentence model, with no custom embedding file.

Is this a known issue on iOS 27? Is there a supported way to request or restore the missing sentence-model asset, or a recommended recovery approach?