This actually applies to anything that has frozen a creature, or reduced your opponent’s creature power to zero. As explained, if you steal a creature that has been reduced to zero, instead of being returned to full power when in your hand, (obviously without your opponent having a Thaumatic Compass in effect of their own) until your Thaumatic Compass disappears from the board, they stay at being frozen/reduced etc.
//Edited Title - Brigby
I had a creature return to fill power after I stole it like 1or 2 turns after I took it.
Can confirm this issue. Played Thaumatic Compass reducing creature to zero. Then played Connive to steal said creature. Power stays at zero while on my side of the board. I can recreate and give screenshots if needed
Thank you for the reports everyone. I’ll inform the team of this behavior.
@TReed If you would, could you submit a ticket to Customer Support including the screenshots? Any additional screenshots or information you can provide would be very helpful.
I noticed this as well when looking into other creature steal failures.
One thing I did see, if the opponent has more than one creature, stealing the 1st (affected by Spires) will cause their next creature to drop into the 1st slot and take on the Spired power = 0 effect, and the stolen creature will return to it’s normal value.
This. If the opponent has only 1 creature affected by spire and you steal it, the spire still affects that crrature until your opponent casts abother creature to take thebspire effect.
Just to piggyback, this isn’t restricted to just Spire. I can’t remember what the cards involved were, but the opponent had out a couple creatures and they had a temporary vigilance effect on them. I stole one of them and the vigilance stayed on the creature permanently.
Also player’s Settle the Wreckage exiles the stolen creature (using Bolas Clutch) when it attacks AI.
That is pretty funny lol. Don’t think I’ve ever used those cards together. 
Same for servos. I stole a marionette master that got buffed by my and Greg’s servos. Came in quite handy, though. She didn’t deal damage when Greg’s servos popped. I used exert influence, so the whole steal mechanic is broken.
Hi Everyone. This issue should be fixed in the upcoming 3.3 build.