when I connedt with out bluetooth device via iOS (Iphone 6S or 7) i can reach up to 185 bytes MTU size.
But when I try to connect it with my MacBook I can only get 104 bytes MTU size negotiated. Is there any particular reason for it.
Try to compare the Bluetooth version ("Bluetooth Core Spec") of your Mac to that of your iPhone (i.e. if the version is 4.0, 4.1, 4.2 or 5)