Missing Storage Space on iPhone 6 Plus
I have an iPhone 6 Plus 16GB Verizon model and although I know this question has been asked a number of times, I can't seem to find an answer that actually makes sense to me so here goes.
The phone was bought new in January 2015 and a backup from my old iPhone 5 was loaded onto this phone. Going through the process, iTunes showed the phone as having a capacity of 14.x GB of space before the backup was installed. After the backup, Settings - General - About shows capacity as 11.8 GB as seen below.
So far so good. I follow that the loss from the touted 16 GB down to 11.8 GB is due to formatting and iOS taking space.
Now the part I don't seem to understand. I just connected the phone to iTunes and did a backup and iTunes shows the phone as having 6.45 GB of available space. If I eject the phone and reconnect to iTunes, it still shows that there is 6.45 GB of available space, yet when I go to Settings - General - Usage, it states that 8.5 GB are used and 3.3 GB are available as seen below.
So, where is the missing 3.15 GB. I clicked on Manage Storage and went through every item listed and added up all the space that these items are using and the total comes to 5.35 GB, yet it is saying 8.5 GB is used in the pic above.
Can someone please explain where the missing 3.15 GB can be found. I have only been using the phone for about 3 months and I don't stream music or videos, etc and I do NOT have iOS 8.3 sitting on my phone waiting to be installed.
I would greatly appreciate it if someone could give me a rational explanation as to where this hidden 3 GB resides and how I can reclaim it.
Thanks.
Dan
iPhone 6 Plus, iOS 8.1.2