Intune - Multi-App Kiosk Mode Android - Managed Home Screen - Can't return to Call Screen

Hi there,
Here is the issue:

• In Multi-App Kiosk Mode for Android
• A user makes or receives a phone call that is long enough to trigger lock screen
• Call can continue indefinitely despite no longer seeing the Telephony UI
• Time to hang up, enter your passcode, you are taken to Managed Home Screen
• From here you can't access the Telephony UI and hence you can't hang up!
• The call interface Telephony UI is not an App on its own that you can Add to the Home Screen

Any ideas welcome.
Ta, Ian Hearnes