[Q] Verizon Note 4 on T-mobile: A few issues topic

Hi, all~ If anything below bothers, forgive me 'cause I'm a newbie :confused:

I'm currently using Verizon Note 4 on T-mobile network. It seemed perfect in the beginning, but a few issues have been found.

1. Touchpad not working when connected to the automated system ?
(when the phone is connected to the automated system, we are often required put a number to select an option. But, even if I touch a number, it never gets through.)

2. Wifi-Calling:
Is there anyway to use wifi-calling?

3. Mobile Hotspot:
Mobile hotspot is not activate.

If you know a solution to any of the issues listed above, please let me know.

Thanks a lot