Ds 4.5 with ASD - is he being picked on?

[sh77]

Ds was recently diagnosed with ASD. He is confident, comfortable being on his own but does want to join in. He doesn't understand the rules of games that other kids get and has older boys assigned to him. He also doesn't get personal space eg touching faces at circle time.
Anyway, he has often mentioned that a boy who is 6 monhs older than him and physically bigger, socially confident regularly pushes him and hits him. He, along with another boy, have been calling him a banana. It makes me uncomfortable. I have had several meetings with his teacher about how to support ds and I think I'm a bit of a pain as they see his traits as developmentally normal for boys. I am sure some level of pushing and name calling is normal in reception but at what point to I intervene if it continues? Sadly, ds will be more prone to bullying but I'm not sure he will recognise when kids are being mean. Any advice?