Automatically sync greyed out in iTunes
I am running Windows 7 and have an iPhone 6. I noticed that recently iTunes was not starting and syncing automatically when I connect my phone to my computer. When I looked in the phone settings in iTunes, I noticed that the option "Automatically sync when this iPhone is connected" is now unchecked and greyed out. It used to work just fine. I can still sync, it just won't do it automatically. Any suggestions? Thanks.
iPhone 6, Windows 7