Siri not recognizing alternate app name in iOS 15

I am working on a Siri integration for a VoIP application. I've added values for both INAlternativeAppName and INAlternativeAppNamePronunciationHint under INAlternativeAppNames in the app target's info.plist. On iOS 14, the phrase "Call [number] using [alternate app name]" launches my app and initiates a VoIP call. on iOS 15, Siri responds with "I don't see an app for that. You'll need to download one." to the same phrase. Is this functionality broken in iOS 15?

Here is INAlternativeAppName in my info.plist:

<key>INAlternativeAppNames</key>
<array>
	<dict>
		<key>INAlternativeAppName</key>
		<string>dialer</string>
		<key>INAlternativeAppNamePronunciationHint</key>
		<string>dial er</string>
	</dict>
</array>