Bein hazmanim is when everybody feels the need to come to Haifa. The buses are so crowded; there are lines in all the stores. These are probably the same people who think there is no frumkeit in Haifa and therefore not a good place to live.
If he is truly unhappy where he is, and his friends’ Yeshiva is suitable, you may want to talk to your Rav about the possibility of transfering him. Yeshiva schedules could be grueling. Subtracting half of Bein Haz may not be enough time for him to refresh and learn as well as he would otherwise.
i think it is twisted that your son has friendds not from hhis yeshiva. a persons yeshiva should pe a place for hm to grow and where the people have the kind of ideals that he wants to have. he should not be mingling with boys from another yeshiva.