Asus Zenfone2 MMS issue

[quizzer]

I'm using ultra mobile (T mobile MVNO) with Asus Zenfone 2. In group messages when I send any message..its going individually to all the members and not as a group. Same way, when they respond, I'm getting individual messages and not in a group.

Is there any MMS setup that has to be done to enable it?

Whatspp works perfectly for group messages. Only the ASUS messaging app has to be addressed.

Please advise.