Fell through landscape at Sandsnas camp site. Travelling South through camp sticking close to cliff edge. Exiting site by jumping over fence and went through landscape. This then repeats over and over. To get out I tried to fast travelling to Narkudden safe house. Success-ish …I fast travelled to the shore/ sea next to the house and continued to fall through the landcape. So I fast travelled to Mudkudden port safe house and was successful. So to continue my task in hand I went back to Narkudden safe house with no problems until I left the house and promptly fell through the ground in front of the steps. At this point I exited to the main menu. This isn’t the first time I’ve gone landscape diving but the game always attended to move the respawn until it hit secure game territory. This definitely didn’t happen this time and fast travel to a sage house and missing is a new development as well as the ground being unstable on return to the area.