Confused

Confused Does anyone know the reason, why I happen to stutter in only specific situations. ​ My normal day to day fluency would be around 80-90% with occasional blocks, but its not too bad. However I have noticed my fluency fluctuate in these situations ​ 1. Talking Alone (Fluency goes from 80% to 99%) 2. Talking to Children aged 1-17 (Fluency goes from 80% to 99%) 3. Talking without direct line of sight(80%-85%) 4. Talking whilst sitting in a car and driving(80%-90%) 5. Ordering food(80% to 50%) 6. Asking for directions(80% to 50%) Can someone explain to me why our fluency fluctuates like this, can it be related to anxiety of some sorts.