useBlockProps() nests wrapper with class name inside block wrapper in the editor

I was bitten by this as well, and it caused me much frustration. I had exactly the same nested block duplication problem that you described above.

I was able to solve this issue by specifying an apiVersion for my custom block.

E.g.:

registerBlockType("custom-cafe-theme/custom-column",{
    apiVersion: 2, // or 3
    title: "Custom Column",
    attributes: {
        imgID: { type: "number" },
        imgUrl: { type: 'string',default: '' },

    },
    edit: EditComponent,
    save: SaveComponent
})