I think I accidentally turned on a setting but I don't know how or which one.
The mesh of my object disappears in edit mode and it is not hidden.
In solid mode, my object looks like this:
But when I go to wireframe mode it only shows an outline of the object where I should see the mesh like this:
In my other projects, I can see the wireframe of the objects under edit mode like this.
As a result, I cannot select individual vertices, faces, and edges when I am in edit mode of that object.
These problems started occurring after I used the keyboard short cuts shift + D and P to duplicate and separate the object.