Can't activate unlocked Pixel 6 phone on xfinity mobile

I just got an unlocked pixel 6 phone (not 6 pro) from Google store, xfinity IMEI checker tool says not compatible, so I decided to insert my son's xfinity mobile SIM card and see what happens, and looks like I can't make calls and no data either, but wifi calling works. I thought pixel 6 is supposed to be compatible with xfinity mobile, isn't it?