display state
Depending on the assembly display-state settings, model edges behind transparent components can be shown or hidden in high-quality ‘shaded with edges’ drawing views. Drawing views seen here are both set to high quality and ‘shaded with edges’ mode: The setting that makes model edges visible behind transparent components…
When changing a component’s display state in the main assembly does not produce any visible changes to the appearance of the model, you might need to clear the appearance override that is sometime created in the main assembly. This video shows both the problem and the solution: