Had dents pop up a few months after, recommended for skin tightening

My concern was acne scars after having c02 my doctor recommended this for tightning of skin . Had one done in the fall saw very little to no results . He recommended I do another one and a few months later I saw what looks like a dent around the cheek . A couple of months later I notice another one . All total I have about 3 that I can see . He said this could happen so for no improvement and new issues I would not recommend . It’s hard to capture it on photo but I e attach one