My daughter has been the same in her joie 360 spin. We got her a group 2/3 car seat and now she looks way too small for the joie! She’s much happier in her bigger seat. I wanted to keep her in the joie rear facing as long as possible but I do think she’s outgrown it. She’s quite chunky (not tall though)
We are having the same problem with our little boy, takes his arms out etc . . We have been looking at getting a bigger car seat . . It’s a minefield choosing one 🤦🏻♀️
We had the same car seat and the same problem and ended up moving him up to the next size car seat just last week. We hoped to keep him rear facing in the Joie until he reached the max height of 105cm (he’s currently 101cm) but decided it was time to move him up now.