Stopped playback played again

I have encountered a strange behaviour of Asterisk when a playback is stopped and then another playback is started.

After the second playback is finished, the first playback is played again. I am using ARI and ari4java.

I guess this shouldn’t be the default behaviour?

Start playback ARI call:
ari.channels().play(channel.getId(), sound).execute();

Stop playback ARI call (the framework generates a DELETE request):
ari.playbacks().stop(playbackId).execute();

Was an issue of my own code …