Weird render with smoke and cycle

Hey there everyone ^^ i’ve run into an issue while doing smoke simulation in blender 2.81 ( for now i don’t understand how the 2.83 smoke sim works :confused: ) so i’m doing my sim and all is fin but wjen i render with cycle it’s doing these weird shapes in the smoke. So i’m asking if you know how to get rid of it ^^

thx for the help !