4yr old boy shy in front of classmates

[Miro8]

Hi,

My 4 yr old is really shy in front of me when I take him to or back from nursery/school. He plays with all the kids when inside, but when we arrive he is hiding behind my back and completely ignoring all of his friends when approached. I don't really understand this as he is not an introvert person and all his friends like him and wants to play/communicate with him. When we go elsewhere he is absolutely ok and don't have problems to communicate with his friends or even kids he does not know.
It is really annoying for me as I feel embarrassed in front of other parents and that he might be left out off the group if he does not change.

Any advise?

He is probably just feeling a bit nervous.
When you have spoken to him about it what does he say?
Is there a way that you can make the transition easier for him. Whilst it may be embarrassing for you I doubt he is doing it on purpose.