You and Jason have history, you were a mercenary, he was Robin He was meant to turn you in…but he fell in love

When the Joker ‘killed’ him…he was reborn as The Arkham Knight, sworn to get revenge on Batman

He never reached out to you, he didn’t want you to see what he had become

So when Deathstroke, your father introduced you to him…you didn’t recognize him due to his helmet, and Jason wanted to keep it that way.