This dynamic components help article states: Identifying Dynamic Components - SketchUp Help It seems Monte will have to explode > re-componentize each in turn to make it behave as expected.
Unfortunately, scaling the non-dynamic parent still creates havoc. The eleven components nested inside are also DCs. That does enable one to scale the parent component, but it’s only the tip of the iceberg. After that, you’ll be able to scale the sofa as you wish.
You can defeat the fixed dimensions by selecting the component, right-click > exploding it, and then immediately re-componentizing it while the pieces are still selected.
