Taken directly from the Marshmallow Release Notes I received:
"After inserting a new SD card to your phone, you will see a notification to set it up. You can choose to use your new SD card as a portable storage or as internal storage:
Portable storage: use your SD card to store your pictures, videos, audio and other media files. You can remove the SD card at any time and transfer it to other device.
Internal storage: in addition to media, you can store downloaded apps and games, all their media and data. The SD card acts as an extension of the internal storage of your phone."
I set my card up as Internal Storage, so what am I doing wrong? Is it becuase I am using my existing card, even though I formatted and wiped it clean?