Please check that attacker cannot use skill on first turn which defender can.
My charactors stuck with 1 turn cooldown in every pvp matches today. Moreover, in adventure mode.
We’ll double check, thank you for letting us know!
I think I’m seeing this too, at least in Adventure mode. Hard to prove one way or another, but I can say that I gave up trying to get my mages to use a skill on the first turn on two different stages today.
Update: Am now able to use skill on first turn in Adventure mode. Seems fixed. 
I still cannot use skill on 1st turn
That’s so weird.
It’s possible I was just incredibly unlucky when my heroes weren’t using fireball in Adventure mode on the 1st turn when I first reported it.
Then, the next day my heroes definitely used fireball a lot on the first turn in Adventure mode, so I assumed it had been fixed.
Didn’t pay close attention in the Arena, but will do so at my next opportunity (in about 13 hours). 