The only clues that I have is that this seems to happen when you are close to a group of otherwise small blocks crowded close to each other, possibly intersecting.
This screenshot showing this same bunch of blocks from in WED. I just recently had to open up the old project just to see it and get this screenshot as otherwise, I have no screenshots on hand of it.
Edit: it's that pyramid that you see there that's where I'm getting the extremely high ref value.