Answered back right quarter of bed not leveling

Hi all, I've had my Robo R1+ for about 1.5 years now and really have enjoyed it. However recently I tried to print a fairly large piece (a circle nearly 8 inches in diameter) and I have found that the back right quarter of the bed doesn't seem to be leveling properly like the rest of the bed. The symptom is that while I have a perfect, squished first layer in the other 3/4ths of the bed, that last quarter just goes down terribly. I have attached pics of 5 outside passes of the first layer to help make it more clear. First pic is of the whole circle, 2nd pic is a close-up of a "good" section, and 3rd pic is from the same area that keeps going down poorly every time.

It seems the printer is not leveling properly. Any tips would be awesome!