Hello Doug! first things first, right click on the background in LayOut and verify that “object snap” is turned on.
Now, let’s talk stacking order…. from top to bottom. Light, Heavy, Hatch A, Hatch B. Do you have something large showing up on the light viewport that would be blocking the wall line work below?
I think I am familiar with the issue you are describing. In my experience it is caused by an object in SketchUp that has the wrong layer applied. Can you take a lap through your model and make sure it is all layered correctly? Email the .layout file to me if you can… Thanks!