Hi Richard. The Pixel 2 does NOT support WiFi calling on Sprint.
Can you explain why? I've used my Pixel 2 on Verizon and T-Mobile and it worked perfectly? Why does Sprint not allow this function, one that many people need to use when coverage isn't sufficient?
Due to the age of the phone and technological issues, updates can no longer be sent which make the phone no longer wi-fi calling capable.
Unfortunately, the real answer is that spint just does not support features like VOLTE or VOWIFI on any phones not purchased from them. They don't support it on any of the new google phones or motorola phones that I know of like many of the other networks. The only unlocked phone that I know of that you could have purchased outside of Sprint is the Essentail PH-1 which is likely only because they were a launch partner. Possibly the iPhone as well.