I have imported this model - (Spaceship - Spear XB | 3D Space | Unity Asset Store) into my project, at run-time the model is still there in scene view but in the game view it dissapears seconds into the game. I have looked at other posts to disable the animation but I dont think thereis any animation with this model.
Check at run-time the model is in the camera frustum (and so visible in the Camera Preview).
Also can try to un-check “Occlusion Culling” in the camera Inspector and see if anything changed to better.