String event "minecraft:become_angry" not working

I am trying to summon wolves that are angry, so am using the command "/summon wolf ~ ~ ~ minecraft:become_angry" and it is not working. It summons a wolf that is still passive and only becomes angry when I hit it. I am sure I have not made a typo and I have also tried other string events that work fine. This also applies to all the other mobs I have tried to make angry, just spawning them in passive. Attached is a picture of the command and the result of the command.