currently, there is no 9-point-option for bed-leveling in the latest firmware-version 2.5.x of the Witbox 2. I am waiting for that feature since it was released for the Hephestos 2, but there is no official release for W2, yet. Does anyone know why not? The Firmware 3.0.0 was online for maybe half a day, but presumably there was a problem of some kind.
Why I answered this thread: I noticed the same problem. For me it was the left rear edge that was slightly lower than the rest of the print bed. So, it seems like it’s not only a problem for you @DaniAzagra.
A working solution for me was to tilt the bed manually while the skirt was printing, to level the print bed more properly. Later, I “measured” the print bed in terms of flatness, but there was no issue with the bed …