Wifi calling

Hi there,

was just wondering if anyone else knew in the community what is going on or any more content what I will describe here as I have also asked in my carriers forum.

On the Apple Watch in the app there is the option to enable wifi calling and I have done this both in my iPhone and Watch settings but if I take my iPhone offline I can no longer make calls from my Apple Watch, ,my idea was that I would be able to make and receive calls without my iPhone nearby if the watch was on a network.

Attached screenshots for more detail.

Thanks,