I have recently set up WiFi calling on my V30 and my wife's V30. When it works it's great since we typically have 0 bars of service at home and maybe 1 bar on the top floor of our home. The problem is that the phone doesn't always connect to WiFi calling. This is the scenario:
Essentially, whenever I connect to wifi, the phone needs to be rebooted for the wifi calling to work. That's pretty bad. I have tried putting the phone into Airplane mode and turning on Wifi but that doesn't work either. The only thing that works is a full reboot. If you search this forum you can find lots of posts of other users with different phones who experience the same issue.
I was in Las Vegas last weekend, roaming on ATT and the phone connected to Wifi Calling flawlessly whenever I connected to wifi networks. It was smooth, fast and reliable. A great experience. This tells me it has something to do with the Fido network and it's not my phone. Especially since both my wife and my phone behave the same way and there's other users on this forum with different model phones who experience the same issue.