Why does 'Canvas stacking' not include components with 'Ignore auto layout'?

I don’t get what’s happening here. I have set the floating menu in the bottom as ‘Ignore auto layout’. And that means it gets located in the top of the layers stack. But in order for it to actually be stacked over the “Content” layer I need to set the ‘Auto layout settings’ to “Last on top”. That feels wrong to me.

Is it a bug or am I missing something?