Hello Roxy, it worked like a charm. Thank you.

One last sticking point though. I also tried working with the AUTO_BED_LEVELING_GRID and whether I put in a value of 2 or 5 for #define AUTO_BED_LEVELING_GRID_POINTS Marlin always probes 9 points. How do I get Marlin to vary the number of probe points, for example how do I get Marlin to probe only the four corners?