8 month old side sleeper

* A*💍 👨‍👩‍👦💙

My son is almost 9 months and recently when he goes to sleep I put him on his back but after he always rolls to his left side to sleep and he will stay like that for a while is this safe ? He rolls bad and forth well and is a very strong kiddo

I have read online it’s good to have babies sleep on their backs till they are a year old but I mean I do try but he seems to be comfy and sleeps well on his left side

I appreciate any feedback

Thank you