I believe it has been mentioned that on the Bonus Wonderland maps some enemies CD does not properly roll over when spinning a "free spin" on the reel. I have noticed it specifically when an enemy (like the Satyrs) is on their "0" CD (before they hit) and when you make the spin and roll a "free spin" the enemies hit (as expected) but the CD does not roll over until after the 3 "free spin" is complete and then you make your first spin after. Where normally the CD rolls over with the first "free spin." (When this happens I am not using "auto spin" so it is not a confusion of which spins are which.)
I just faced a similar (but slightly separate issue). I was running the Insane level of the Wonderland Fire, during the 3rd wave (with the Blue and Red Satyr) I waited until both had a CD of "0" and used my 6* Valkyrie's ability to nullify red for "3" turns, then made my spin. When I made my spin, I got a "free spin," the Blue Satyr hit for its normal hit while the Red Satyr hit for a "0" (as expected), but after the free spins ended the Blue Satyr's CD rolled over while the Red Satyr stayed at "0"
This is the first time I have had the 2nd scenario happen, but it is also the first time I used that team. I have had the 1st scenario happen all the time on this and the Wonderland Ice maps.