I switched to a new iPhone but the Apple Watch won’t unlock the iPhone now.

Hi I used a iPhone Xs and my Apple Watch since 14.6 was installed and was very successfully using the feature that unlocks my iPhone when I was wearing a mask and had my Apple Watch on. Since then, I have upgraded to iPhone 12 pro and now the phone won’t unlock with the watch. I have unpaired, re paired set up as new erased the watch and started fresh and nothing works. Has anyone else been able to solve this?