My Son's behavior outside home

[Guest guest]

My 2 year old son on the Spectrum is a happy kid at home. After starting the

diet and supplements he is improving and is quite responsive though not talking

yet. But when we go to our friend's place or when friends visit us, he becomes

happy but is out of control and hyper. He is kind of in his own world and

doesn't recognise his dad even. He is not responsive at all and it looks like

anxiety attack to me.  Once we get back home from our friends place or if they

leave our home he is quite normal again and is responsive. Anyone seen this kind

if behavior? Thanks for your suggestions.