People I'm calling complain I keep cutting out. Am I getting Wifi calling?

Have finally worked it out! Even though Wifi calling is enabled, my phone is always using the signal from the mobile mast to make the call, even if that signal is very weak, hence the poor sound quality. After trying everything else, I switched my phone to airplane mode, making sure the Wifi was switched on. This disconnected my cellular signal to the mast, and thus forced my phone to use Wifi calling. All I have to do then is remember to switch airplane mode off when I leave the house, so that I can use the mobile signal as usual to make and receive calls.