The quest titled “???” is located somewhere on the map. There is no option to set this quest as active and track it.
Please open the Witcher Senses menu and find a yellow question mark that will show the exact position.
Sometimes The Witcher: Monster Slayer may not be able to place or relocate your quest. That is because there are no Points of Interest for the game to find a suitable location nearby.
In this case, you have to move to another area. It may occur in the following areas: mountains, seasides, lakes, forests, or roadless areas.