I have this happen in my games (one in SV and one in Riverview). Haven't found a fix for it either, placing a new lot or building doesn't make it go away. Same with reloading the game, clearing caches & whatnot. I just try to live with it. And yeah, I've never even seen CAW.
I've played with those games for quite a while since the glicthing started, and it never fixed and always stays in the exact same space, so I guess it's permanent. So my guess is there's no other fix than start a new file like I guess you did.
Another thing that happens in my games: If I delete houses and replace them with new ones, when I go to map view, it still shows the old contents of the map. Only when I zoom in it finally loads the actual contents of the lot. I wonder if this is connected to the other graphic glitch (it's not the same lots tho). This one also seems unfixable; I've had a consignment store which in Map view looks like a small starter house for several weeks now. They have right icons but look like the original map. A bit annoying...