When your hand is full and you sell the patient scout you get to discover a minion but it disappears, no warning about the full hand whatsoever.
That’s not a bug. You have to pay attention yourself so this doesn’t happen.
There also is no warning in Hearthstone when your hand is full and you will burn a card the next time you draw.
having a full hand means you dont have room for more cards…if it added it it wouldnt be full…
Any effect that tries to add a card to your hand will fail, when your hand is full.
This isn’t a bug.
It’s your job to know when your hand is full.