I was trying to farm a few Calliope early, but gave up after 3 runs in a row with 0 total drops. I moved onto the last map and I've still had below average luck, but at least I've gotten something.

Charlotte x 1 Valerie x1 from 3rd map on my only try. I should have known my luck was done after this drop.
Charlotte x 1 Calliope x1 on 6 tries
Charlotte x 3, Pallis x 1, Christopher x 0 on 8 tries.