The only shares that have files on the cache are all set to be prefer, which means that mover will try to move them TO the cache drive from the array (appdata, domains, whatever share starts with "U")
What space are you expecting to be seeing available?
Possibly, your VM vdisk isn't "sparse", so it has grown to be the maximum size that you've set (by default, it never shrinks, and only grows). See here:
https://forums.unraid.net/topic/51703-vm-faq/?tab=comments#comment-557606