Android says "out of storage", Link2SD says "lots of empty storage"

[Adeleblancsec]

Could really need some help with this:

I have root, I have an 16 GB SD card partitioned with 8 GB Ext4, I have Link2SD, I have sooo much free space; but Android says I'm out of storage space.

Titanium Backup also refuses to make backups because of lack of space, but lets me install apps from backup using TB.

Screenshot below.

Could someone explain this, and help me?

(And yes, I have autolinked apps through Link2SD, so that works)

Device:
Sony E1 (D2005)
Android 4.4.2
Kernel 20.1.A.2.13 (Android says , but I have flashed the 20.1.A.0.47 to be able to root)
Rooted
16 GB SD-card (8 GB Fat32, 8 GB Ext4; partitioned with Github method)