Volumio iOS pause button

I have installed Volumio on Rpi2 with HifiBerry AMP.

When I start a song via a browser (Chrome), music is playing fine.

When I hit the pauze button on my iOS app, the music stops indeed. However I would expect the “pause button” to turn into the “play button” so I can restart the music again from my iOS app. This is not the case.

As a workaround I go to the browser, hit the “stop button” (which turns into a “play button”) and I can start the music again.

Seems like a bug. Can someone confirm? And if so, where can I log these things?