I'm using a Prusa clone with Ramps 1.4, Marlin 1.1.5 and an inductive proximity sensor Z-probe. Due to the design of the printer, the X and Y end-stops and the Z-probe are not exactly aligned with the heated bed, so I must use Marlin's Home Offset feature to align the coordinate space to the print area, using the G-code command
M206 X-18.5 Y-2.5 Z1.1.
I am now attempting to use Marlin's Unified Bed Leveling feature to compensate for a slight but significant curvature of the bed.
Unfortunately, it appears that the Mesh Validation Pattern command (G26) is not taking the Home Offset into account when printing a test pattern. The printed pattern hangs off the left side of the bed and the center printed circle is clearly misaligned with the center of the print bed by the bed offset amount.
Does this suggest that my firmware is misconfigured? Or is there an alternative method for aligning the mesh validation test pattern with an offset print bed?