Photos app taking up 5GB in "other" storage
I've started paying for the 200GB iCloud storage to give me some space on my 16GB iPhone 5c.
I have about 30GB of photos and videos which are in the Photos app on my Mac and in the cloud.
I have the "Optimise iPhone Storage" selected but whenever I take videos or photos it just makes the storage of my iPhone smaller. To the point where I had no storage and deleted all the music and apps off my phone. However if I go to some recent photos and videos I have to download them from the cloud (suggesting they are deleted off my phone and uploaded to the cloud).
I then plugged my iPhone into iTunes and see theres 2GB of the Photos (presumably all the optimized photos / thumbnails in moments) + 5GB of other!
This happened last month and I did everything, deleted emails, restored from backup, restored from just iCloud and they all reduced the other to 1-2GB which seems ok. But a few weeks down the line it's back up to 5GB, which never used to happen before I started using Photos and paying for the iCloud subscription.
I've deleted the "recently deleted" photos so it isn't them either.
Is anyone else having this problem? Why when storage is low (say under 500mb) doesn't Photos upload all photos and videos to the cloud (and delete off phone) to free up storage instead of me having to delete photos and apps?!
Would really appreciate any help thanks.
iPhone 5c, iOS 8.3