It seems like educated cards are not shielded immediately when they are played. I just played an Educated PC in slot 2 and it was hit for 100% of the opponent's attack. Then when it was my turn again I saw the shield animation go over the card and on my opponent's next turn there was an attack but zero damage. Shouldn't the shield activate immediately when the card is laid, and not when it becomes "active" or something?
UPDATE: It seems to be shielding only one Educated card at a time for me. I've got 3 on the board but the shield animation only appeared over one, and the others both took a full attack. All are Educated, PCs and item cards both.