Moving android_storage to sd card

Xperia XA2 plus
OS 4.5
14gb sd card formatted and mounted

Hi guys Ive been trying to free up space on my phone and migrate some files to the sd card in my xperia, mainly the android_storage and my media (photos/videos). Ive tried doing this through the phones file browser (I am using the updated version) and also just trying to move it on my computer with the phone plugged in via media transfer. So far nothing seems to work, I kinda thought Id be able to simply copy/paste the android_storage root onto the sd card but whenever I move it onto the card 90% of the contents dont copy. It seems the info about using sd cards on docs.sailfish is missing ( Any tips or help appreciated,

Hi, at least from here you can find some info about the topic: Moving files between a PC and a Sailfish Device | Sailfish OS Documentation
Also here is something which might be useful:
SD Card Format and Encryption | Sailfish OS Documentation