Just a wild guess, but make sure not to use DLSS if playing in G3D, as this can cause black screen.
If I remember correctly, Days Gone takes quite a while to load at startup, and it’s possible that on occasion it may take multiple attempts.
Less likely, but on rare occasion I’ve seen G3D games that have the title or menu screen blacked out, but loaded in game looks fine. In these cases you can switch to Z3D or turn off 3D to see the title screen, then switch back in game.