Why does Vyvanse make so much less anxious?

I have been testing ADHD meds for the first time in my life ( 5 days now ) and I don’t understand how Vyvanse(20mg) just makes me so much less anxious during the day, when one of the side effects is anxiety. For now I only see a tiny improvement on attention and executive functions . However , it’s night and day when it comes to anger, overwhelm and anxiety but I don’t get why it’s making me just lighter overall but not doing much on executive fonctions or focus ( or maybe it’s too subtle ?)