Previous audio can sometimes be briefly heard when playing new content

[defagos]

Is there an existing issue for this?

• I have searched existing issues and found no similar bug report.

Description of the problem

After having used SystemVideoPlayer, VideoPlayer or AVPlayerViewController and seeked, playing content elsewhere in the demo app (the easiest is to use a playlist demo) reveals that audio of the previously played content can be briefly heard when playing new content.

If the system player UI is not used before no issue arises. This feels like a weird AVFoundation or AVKit bug.

Note that this bug is not new. I could reproduce this bug with version 10.0.0 of Pillarbox, for example.

Relevant stack trace or log output

None

Reproducibility

Always

Steps to reproduce

1. Run the Pillarbox demo and one of the the playlist demos (e.g. URNs). Switch between items quite fast and observe that sound ends/starts sharply as expected.
2. Play other content randomly in the demo (except content played using SystemVideoPlayer demos). Repeat step 1 and verify nothing has changed.
3. Play one of the vanilla system player demos (those using AVPlayer directly, thus not related to Pillarbox at all, e.g. the Trickplay example) but do not seek and close the player. Repeat step 1 and observe that nothing has changed.
4. Play the same content with the same player and seek in the content. Close the player.
5. Repeat step 1. You can observe that transitions between items are not as shap as before, with sound producing a kind of glitch. If you repeat this step several times you may notice that the glitch seems to belong to the content that was played just before.

Library version

14.0.0

Operating system

iOS 26.2

Code sample

None

[defagos]

We could have hoped that #1416 would have fixed this issue, like it did fix other behaviors (see #1427). After testing version 15.1.1 the answer is sadly negative.