I am not familiar with iPhones but wondering if there is a setting that limits hotspot to a certain number of devices. Even though Android was never enforced I had to go into the hotspot setting then to manage devices and change the device limit, I changed it to 10.
Which plan is your friend on? Not sure if there is a new base plan but there is the new plus plan and that has the device limit removed. If your friend is still on the old plus plan(it is begin referred to as V1+) he would need to upgrade to the new plus plan(V2) to get the multiple device limit including the 10Mbps speeds the hotspot offers. Bad thing is if your friend has any promos or discounts attached to old plus plan by upgrading to new plus plan they are removed and he would pay full price($45).
You could have your friend also ask CS to re-provision his SIM but if he is on the old plus plan it won't do any good.
