K2 First Layer Issues

So, Things were going pretty well, have gone through 3-4 rolls of filament with no failed prints; however, a few days ago I started having problems with the first layer. See attached photo:

SO I learned how to see my bed levelling mesh and it looks symmetrical but warped like a pringle

Any suggestions?

Z-offset is a little low, 0.05-0.1mm my guess, adjust it should get rid of the ripples.