Downgrade to WPA2

If you can't figure it out take it to a T-Mobile store and request assistance. If you cannot get the iPhone home internet mobile application to work BE SURE TO SHOW THEM that. I am sure they know it is a problem but I have not seen any indication they are doing anything about it.

If you have an Android tablet you might be able to load the application on that from the application store.

I use an old Pixel phone from time to time but the battery is dead, again. It is old so that is about all it is good for now.