Did you check out gameplay videos too?
If the witcher senses don‘t show the inscription, you might have to load an earlier save game (before starting that part of the scavenger hunt).
In case you are playing with mods, that can also mess up things.
Also check out this information:
Welcome to CD PROJEKT RED Technical Support! Here you will find help regarding our games and services, as well as answers to frequently asked questions.
support.cdprojektred.com