Hello,
I recently tried a setup in Hearthstone Battlegrounds where I utilize the battlecry of Reverber Drake (Cast Echoing Roar - +2/+2 end of turn effect on a dragon). Combining this card with Permanent dragons such as Tarec and Persistant and then triggering it during combat with both Rylak (+reborn) and Macaw - would seem like a good combo. With that said, my dragons showed it had additional Echoing Roars on them thereafter, but they never got any additional stats… This seems to be some kind of bug, hopefully you can fix it.
All the best,
SEVON