Render image rendering incorrectly with a checkered pattern I am learning Blender and following some Udemy courses. I added some materials to the model and in the render viewport, it looks completely fine in that nothing looks broken.

When I add a camera to the scene and try take a render image, it's almost like the materials are missing and it comes out all spotted and checkered looking.

Does anyone have an idea what might be causing that to happen?
What @Jachym Michal said is correct. Press ALT H in the viewport, your second object should appear, otherwise search in the outliner.  Btw. this irregular pattern of triangles and weird stripes is called z-fighting, where z is the distance to the camera, it means 2 faces occupy the same space and the camera has troubles deciding which one to show in each sample.