we've seen a lot of reports on getting softlocked in various points - the Isle of Grom Tutorial, various Missions and/or Challenges. the Full Circle team are working to indentify the cause of the...
Ideas
If you tap the left direction button (Social & Spectate Menu) and exit while loading a Spectate camera, there is a chance that it will visually remove all player characters (and moving vehicles for some reason) from your game.
Attempting to start a mission while your game is like this will fail and keep you from entering menus; forcing you to restart.