Here is what happened during my match:
1. I completed the Untapped Potential quest and received the Ossirian Tear passive reward as expected.
2. At that point, my Choose One cards (such as Wrath and Nourish) correctly gave me both effects.
3. Later in the match, I played Malfurion the Pestilent.
4. After transforming into the Death Knight hero, my Choose One cards no longer provided both effects. For example, Wrath only gave me the option to choose between “Deal 3 damage” or “Deal 1 damage and draw a card,” instead of providing both effects.
5. This change occurred immediately after playing Malfurion, and it persisted for the remainder of the game.
As far as I understand, the Ossirian Tear passive should persist for the entire game, regardless of whether a hero card is played. If this is not intended, I would appreciate clarification. Otherwise, this may be a bug worth investigating.