Dear Wizards Support,

After gaining control of my opponent's turn using Emrakul, the Promised End, one card in their hand became hidden. Specifically, the card they drew at the beginning of their turn was not revealed to me, even though it should have been visible.

According to the card's effect, I should be able to see all cards in their hand during the turn I control. Could you please clarify if this is a known issue or an intended interaction?