Wi-Fi Calling feature on Pixel - How do I tell if it is using it?
I have a Samsung, so behaviour might not be identical (although a quick google seems to suggest it is near enough). When my phone determines that cellular signal is not strong enough and switches to wifi-calling, an icon does appear in the status bar next to the wifi indicator. It looks like a phone icon with the wifi logo above it. The phone icon in the dialler also changes to this modified version.