Does canada or any other abroad country changes ppl?

So i started my school just 4 days ago where i met new ppl some were afgani some were russian and etc, and fortunately got to meet Bangladeshi people aswell but they act if they got frnds with another bangali person that would make tham uncool like how funny is that i haven’t seen on group or anyone being frnds who are from bd but at the sametime if i see in my surrounding countries dude they look for them and talk like its never their frist time talking with eachother..y ppl are like this??