Chin acne is quite common and typically caused by inflammation and the buildup of sebum (oil), dead skin, and/or bacteria. Chin breakout meanings can vary. For the most part, chin acne in women is caused by hormonal changes, genetics, and stress.
https://www.pandiahealth.com/what-does-acne-on-your-chin-mean/#:~:text=Chin%20acne%20is%20quite%20common,changes%2C%20genetics%2C%20and%20stress.