Following losing all my phone data/documents/pictures from not backing up I bought this drive to easily back my phone up. Not the case, plugged it in, downloaded the driver, set up security and when I try to back my phone up I get a message there is insufficient storage space and I need to lose 10 gb files. The back up it 10 gb total and the drive has free 456 gb space. Can't find answers elsewhere, can anyone help?