I haven't done much drawing lately and have noticed something new in AC23. I have a surveyor's survey as a trace reference in a worksheet and have a new floor plan over the top. My slab in the new floor plan obscures the trace reference under it. I remember that not happening before. The trace reference, when selected, was always visible as a default with light greenish-grey lines. When I turn the new slab off, in layers, the trace reference appears as it should. Am I missing something or have I forgotten a setting?