I went to transfer folders over to a mac using the Android Transfer app, once I connected it it wasn't showing two of the photo albums I wanted to transfer.
I unplugged the phone, checked the phone directly and two of the albums have gone. They were on it before I plugged it in.
I have cleared the data cache for gallery and files, and I have also allowed to show hidden documents (the .nomedia thing) and I can't see them anywhere. They are also not on the mac as I didn't get the chance to actually transfer anything.