I get knocked back and can't break free until the knockback completes. If someone spams it you get knocked back multiple times. Also while you can't be chain stunned by templar javelin knockback you also cant break free until the knockback completes. Sometimes you'll be floating in the air for several seconds before the actual CC takes effect. You need to remove knockbacks from this game and just make everything a stun because they don't work properly.
Also I was stunned by permafrost earlier and it wasn't allowing me or another group member to break free.