I have used LR since its inception and don't recall that I have ever had this issue until recently.
While editing still images in Lightroom, I keep getting these odd shifts in the images that make them momentarily mega washed out, almost like a spike in gamma. It usually occurs when I use quick adjust on an image (or a few), but sometimes it just does it on its own. Closing the LR window and immediately reopening it solves the issue, but only for that instance. Otherwise, I have to wait a moment for it to fade back to normal.
I can't tell, but it doesn't seem to effect the rest of my monitor, only the images in LR.