Loud and bubbly at home - shy outside

My October little one LOVES life and is a loud vibrant boy. I’ve noticed that he takes time to warm up to new people/kids/places but starts to come out of his shell after a while. He won’t be as loud as he is at home but he is happy to play and share with other kids. He goes to nursery two days a week and they said he tends to be reserved which shocked me. I thought he would be well and truly used to it all and fully warmed up and being his loud happy self as soon as he steps foot in there. He has been attending for a year now and loves his key worker, I get to see him on camera too on the days he attends and he is playing away and not hiding/crying etc. Has anyone else got a child who is comfortable at home but not so much at nursery or with new people/places? Is he just shy elsewhere and more comfortable at home?