I'm using marshmallow 6.0.1
I think from 5.0 lollipop moving files in external sd android/data folder is not possible. Files created by apps, mostly received from wifi sharing are stored inside android/data/<app folder> by few apps. These files cannot be directly moved to any root directory of external sd. When moving it's copying and deleting those files, like moving to another drive even thought it's the same drive .
This makes a particular problem when the external sd storage is low. For an example in order to move a 2GB file from external_sd/android/data/<app folder> to external_sd/Movies system required additional 2GB, it copies the file and then deletes the source file. So moving is not possible if the free space is below 2GB .
Internal sd android/data folder doesn't have this issue, moving files is direct and quick(without copying and deleting).
I'm guessing it's because of the owner permissions of the android/data folders and root folders . Is there any workaround to make files move without copy-moving from external_sd/android/data folder to external_sd/<any folder other than android> without root .