Since the last update, every now and then, when the opponents have a special ready, they can retaliate with that special, while you hit them in the block.
Now, to be honest, I'm not sure if this is a bug, but I just can't remember being like that in the past, or before this month update. This happens every now and then, for example in 10 minutes it only happened twice, while in other cases it happened 3 times in 2 minutes or so.
Below is a video with 2 examples :
https://youtu.be/Yogbm9m_MxA?t=3