Do you have them someplace where they can have the normal light and dark cycles? If you do, try getting them in a darker spot. In the wild a Ball would be curled up in a moist dark termite tunnel and would come out in the night.
If you have them in a darker spot, try something a little lighter.

If you have feeders in the same room with them, get them out of the room and far away. Present the room prior to feeding.

I'm sure you mentioned it, you have your humidity up to 60%?