Announce: true works but only if it's TTS?

I’m running a PiCorePlayer instance to handle media files and streaming media to my amplifier system.

If I’m using Music Assistant to play something from a Spotify feed and I initiate a TTS message on that media player, I hear a bell ring, then the text is announced, and moments later the music resumes.

However, if I trigger a local MP3 file using the following:

{
    "media_content_id": "media-source://media_source/local/sounds/coffee_maker/halloween/off/10.mp3",
    "media_content_type": "music",
    "announce": "true"
}

the audio file plays, but MA doesn’t resume the previously playing media.

Any ideas? Clearly the PiCorePlayer supports resuming playing if it works with TTS.