Selecting Sub-Objects command is not working as it should

Using Rhino, trying to select sub-objects using the shortcut Ctrl+Shift+Left-Click I should be able to select any surface or any curve that is part of a polysurface to edit the polysurface, but something in my rhino software isnt allowing me to select any curves with this command. I can still select surfaces, but for some reason curves wont select. It was working yesterday, but I’m guessing I some how bumped something on my keyboard or on my screen, turning the curve sub-selection off. I have checked the SelectionFilter, but everything is checked, like it should be. Does anyone know how to fix this?

Sub-object selection will (should) allow you to select surface and polysurface edges, but not isocurves or independent curves currently. If that’s not the case and “Curves” is indeed checked in your selection filter, I don’t know what might be wrong there… --Mitch