UserAgent: Mozilla/5.0 (X11; CrOS x86_64 10575.55.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36

Steps to reproduce the problem:
1. Download an MP3
2. Click on it to open it in the ChromeOS media player
3. Press the play/pause keyboard button

What is the expected behavior?
The audio is played/paused (regardless of whether or not the media player app has focus)

What went wrong?
Nothing happens.

WebStore page: 

Did this work before? N/A 

Chrome version: 67.0.3396.87  Channel: n/a
OS Version: 10575.55.0
Flash Version: