iOS 27.3 beta: Apple Intelligence works in system UI, but Foundation Models returns deviceNotEligible on a mainland China iPhone Duo

Hello Apple team,

After updating an iPhone Duo purchased in mainland China to iOS 27.3 beta, Apple Intelligence appears to be available at the system level:

• Apple Intelligence is visible in Settings.
• Pressing and holding the side button successfully activates the system assistant.
• The multicolored glow appears around the edges of the screen while using it.

However, when developing an app using the Foundation Models framework, the on-device model reports that this device is not eligible, and an actual generation request is also rejected.

Environment

• Physical device: iPhone Duo (iPhone19,4)
• iOS version: 27.3 beta
• OS build: 24C5037i
• Build toolchain: Xcode 27.1 / iPhoneOS 27.1 SDK
• Diagnostic app deployment target: iOS 26.0
• Developer Mode: enabled
• Reported locale: zh-Hans_HK

Minimal reproduction

We built and installed a separate, minimal diagnostic app to rule out our main app’s business logic. It reads the model availability and attempts one request containing only synthetic test text:

let model = SystemLanguageModel.default

print(model.availability)
print(model.supportsLocale(Locale(identifier: "zh_CN")))

do {
    let session = LanguageModelSession(
        instructions: "Reply briefly. This is a synthetic device diagnostic."
    )
    let response = try await session.respond(to: "Reply with OK.")
    print(response.content)
} catch {
    print(String(reflecting: type(of: error)))
    print(String(describing: error))
}

Results on the physical device

availability:
unavailable(
    FoundationModels.SystemLanguageModel.Availability
        .UnavailableReason.deviceNotEligible
)

supportsLocale(zh_CN):
true

error_type:
FoundationModels.SystemLanguageModel.Error

error:
This device does not support Apple Intelligence.

The availability remains deviceNotEligible after the request.

Could you please clarify:

1. Does the mainland China Apple Intelligence rollout in iOS 27.3 beta include third-party access to the on-device model through Foundation Models?
2. Is this a known issue or an expected limitation of this beta?
3. Is building with Xcode 27.3 / the iOS 27.3 SDK required for this access?
4. Does enabling the Qwen extension affect Foundation Models eligibility, or is that extension independent of SystemLanguageModel.default?

We can provide the minimal diagnostic project and additional diagnostics if needed.

Thank you.