I have a Sony Experia Z5, and it had tons of downloaded "available off line" music on it...

Now it has NONE!... The green arrown to indicate it's had been downloaded isn't even there any more (I know sometimes it's greyd out). There is absolutely no indication that there is any downloaded music, nothing!

I've checked the "available offline" setting and it is selected, I've done a phone reset and logged in and out on both my phone and laptop. On my laptop all my downloaded playlists appear to still be available off line, but any of the albums I downloaded are no longer showing as downloaded or available off line.

For the record my laptop is a Dell xps-13 running windows 10 and my phone is running Andriod 6.0.1 which hasn't had an update in a while so can't be that...

Because I use a mobile broadband service with limited data, downloading all my music again in one go just isn't an option, let along trying to remember all the music I downloaded!?...

Someone please tell me **bleep** is going on here, starting to loose my rag considering this is a service I'm paying for!