The corner circles are essentially selective brimming, when all is said and done. Great for larger pieces (4"+) where you don't want a brim along the entire length.

Is your lift occurring as soon as the first couple of layers are down, or only after you get half a dozen layers down?

If the former, check that your bed is flat and level and the Z height is set properly. If the latter, it's most likely due to the top layers cooling while the bottom is still warm (heated bed), and the countermeasures are to heat the upper layers (heater or heat lamp) or anchor the bottom more firmly (even going two or three layers with your prim/print stamps/davopads.