Crovax the Cursed reduced to 1/1
Sac a creature to Crovax the Cursed and he becomes a 1/1 instead of a 5/5
Can confirm. More specifically, the effect that should add a counter to Crovax (aka if you do sac a creature) instead resets the number of counters to 1.
I would like to say this also happened to me, and I lost the match because of it. I chose to sacrifice a creature and Crovax became a 1/1 instead of a 5/5.
This bug reduces the number of counters on Crovax to 1 if you choose to sac a creatue on upkeep regardless of how many counters on him at the time.