Today we had a track to be played before the service and another after it. The track was attached as audio to a slide.
On both occasions the track did not start first time. In order to get the music to play I had to move off the slide with the audio, back to the one before and move on a second time.
On both occasions the previous slide had been on display for quite a few minutes.
If the developers are having a look it is a presentation with a name starting 200219.