A quick question. A material with 100% opacity is applied to a component. Which to my feeble brain would imply that the component behind that component should not be visible.
But this is not true. If you change the angle or zoom in and out the components behind become visible.
Maybe in addition to the material you applied on the component, you also applied material on the faces inside the component. The later gets priority.
The best if you share your model and someone can teke look on it…