iOS 18 MapKit discrepancy between physical devices and simulators

I have noticed a discrepancy between behavior on physical devices and simulators in iOS 18.

I am using the latest MapKit APIs to fetch MKMapItems using the following MKLocalSearch:

private func performLocalSearch(_ query: String) async throws -> [MKMapItem] {
    let request = MKLocalSearch.Request()
    request.naturalLanguageQuery = query
    let search = MKLocalSearch(request: request)
    return try await search.start().mapItems
}

This returns an array of MKMapItem on both the simulator and physical device. The key difference is my physical device (iOS 18.1.1) is missing the MKMapItem's identifier value. On the simulator, identifier is always populated in addition to my search. Any ideas on how to resolve this?

The new MapKit API for those curious:

@available(iOS 6.0, *)
open class MKMapItem : NSObject {

    @available(iOS 18.0, *)
    open var identifier: MKMapItem.Identifier? { get }