Refurbished Pixel 3XL

Got two Pixel 3XLs (his and hers) and when mine arrived, I checked to IMEI and I'm fine. However, the one for my wife is saying it will not work. How can this be with them all being factory unlocked from Google? According to the forum, @ComcastChrisL ... you may be able to help. Could you tell me what info you'd need to be able to let me know if I need to return this phone? I appreciate it in advance.