AppIntentVocabulary (INPlayMediaIntent) is unstable.

I am developing an iOS app that supports INPlayMediaIntent. We are trying to increase the recognition rate of content names, which are song titles, using AppIntentVocabulary. As a sample, some extracts are shown below.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>IntentPhrases</key>
	<array>
		<dict>
			<key>IntentName</key>
			<string>INPlayMediaIntent</string>
			<key>IntentExamples</key>
			<array>
				<string>Mezamashi Appで湖畔の朝を再生</string>
				<string>湖畔の朝をMezamashi Appで再生して</string>
			</array>
		</dict>
	</array>
	<key>ParameterVocabularies</key>
	<array>
		<dict>
			<key>ParameterNames</key>
			<array>
				<string>INPlayMediaIntent.playlistTitle</string>
			</array>
			<key>ParameterVocabulary</key>
			<array>
				<dict>
					<key>VocabularyItemIdentifier</key>
					<string>ID1</string>
					<key>VocabularyItemSynonyms</key>
					<array>
						<dict>
							<key>VocabularyItemPronunciation</key>
							<string>aogamagaeru</string>
							<key>VocabularyItemPhrase</key>
							<string>青ガマガエル</string>
						</dict>
					</array>
				</dict>
				<dict>
					<key>VocabularyItemIdentifier</key>
					<string>ID2</string>
					<key>VocabularyItemSynonyms</key>
					<array>
						<dict>
							<key>VocabularyItemPronunciation</key>
							<string>kohon no asa</string>
							<key>VocabularyItemPhrase</key>
							<string>湖畔の朝</string>
						</dict>
					</array>
				</dict>
				<dict>
					<key>VocabularyItemIdentifier</key>
					<string>ID3</string>
					<key>VocabularyItemSynonyms</key>
					<array>
						<dict>
							<key>VocabularyItemPronunciation</key>
							<string>kumageratachi no uta</string>
							<key>VocabularyItemPhrase</key>
							<string>クマゲラたちの歌</string>
						</dict>
					</array>
				</dict>
			</array>
		</dict>
	</array>
</dict>
</plist>

When running on the iOS 17.5 simulator in Xcode 15.4, the results are as follows.

mediaName = VocabularyItemIdentifier

mediaIdentifier = nil

<INMediaSearch: 0x6000026212c0> {
    reference = 0;
    mediaType = 0;
    sortOrder = 0;
    albumName = <null>;
    mediaName = ID1;
    genreNames = (
    );
    artistName = <null>;
    moodNames = (
    );
    releaseDate = <null>;
    mediaIdentifier = <null>;
}

However, when running on an iOS 17.5 device, the following applies.

mediaName = VocabularyItemPhrase

mediaIdentifier = VocabularyItemIdentifier

<INMediaSearch: 0x301efd9e0> {
    reference = 0;
    mediaType = 5;
    sortOrder = 0;
    albumName = <null>;
    mediaName = 青ガマガエル;
    genreNames = (
    );
    artistName = <null>;
    moodNames = (
    );
    releaseDate = <null>;
    mediaIdentifier = ID1;
}

The results are not stable, for example, sometimes everything else returns null. I have tried everything, but it is just taking a long time.

Does anyone have any advice on this?