I have exactly the same problem. During my first visit to the Genius Bar, they tried a reset which only left me having to re-enter all my setup information. No effect on tap to wake. They indicated next step would be a full OS Reload and if that did not work, a screen replacement. I declined to proceed at that time as I needed to double check all pics backed up.
I decided to load iOS 12 Public Beta to seen if it fixed the issue. It did not, so returned to Genius Bar where they politely informed they do not support iOS 12 at this time. Having many more pics on the phone since previous visit, again wanted to double check backups before proceeding.
Now running full pic backup to PC and once that is finished will make another Genius Bar appointment when they will probably have to take phone for a screen replacement.
If that doesn’t work, then I guess they will have to replace phone with a new one.