3-month old sleeping against side of bassinet

My 3-month old son started not only flipping onto his side to sleep but wiggles himself right to the edge of the bassinet. The sides are mesh but should I be worried? It’s not pressing against the side of the bed and he’s no longer swaddled but in a sleep sack.

I’ll shift him back to the middle of the bassinet but he’ll wiggle himself to the edge shortly after! He also whale tail slams his legs onto the side too…

Is this safe? What should I do?

Side note: any ideas why his naps are terrible in his crib (naps are in his crib while bedtime is in our bedroom) in a sleep sack but nighttime is pretty decent (only a handful of wake ups for the soother & one night feed)?