iPad Air and iPhone 5 'out of storage space issue' with Apple Music

Having upgraded my iPad Air v1 and iPhone 5 to iOS 8.4, I was left with approx 2gig of storage space left in each of my two devices (after reboot). I thought that was plenty of space left after the upgrade.

I signed up for the Apple Music free 3 month subscription. I chose not to download any music to play offline, choosing instead to play any songs and playlists over my home wifi, via streaming... It's rare I store any tracks on my devices and use iCloud to stream my purchases.

On day 2, I went to bed with my headphones on and set my iPhone to play an old playlist from my iCloud (I'm an iTunes Match subscriber too)... I drifted off to sleep and in the morning I discovered my iphone was displaying the message 'storage space almout full'.. I looked in settings/general/usage and music was showing very little space used, but my available storage was 0 ... The phone was absolutely full.

I turned off 'apple music and iCloud' in settings/music and then went to the Apple Music app itself and signed out my account. Suddenly 2gig of available storage space reappeared. My thoughts were ... the app is causing some kind of memory leak and using up storage when it is streaming.

So earlier today I got my iPad Air and played/streamed a different music playlist, without downloading any tracks again and eventually I got the same message 'storage space almout full'... I quickly fixed the issue again in exactly the same way by turning off Apple Music and signing out the app... And my available storage space of approx 2 gig returned.

.. So I think the new Apple Music app is 'leaking' and taking up storage space during streaming. I was just wondering if anyone else has begun to encounter this memory problem (or similar) with the new app?