Then the logical thing to do if you're having problems is to turn it off again in the menu. Hiding the capability behind a service dialing code seems ridiculous. It works great for me in areas where I have WIFI but not much cell reception after I dial the code and then enable it. If your network doesn't support wifi calling that is a separate issue and even in the menu, under the wifi calling toggle it literally says that your carrier will have to have wifi calling enabled for it to work as a disclaimer. So why hide it, and the disclaimer, in the first place? Furthermore, even if it is hidden, it is still on the phone. A way to keep the menu option permanently visible, even if you have to dial a code, would be great because you currently have to dial the longest service code ever, every time you reboot. This is just disappointing for ASUS.
