Yes, i use the actual firmware and it checks 3 positions with each nozzle. I started with a manually levelled bed, having done a test print with nGenFlex and than activated active bed levelling.
The nozzles are not 0.5 mm above the surface. The process started with core 2 directly on the surface moving the bed up and up and up so the spring of the core are notably compressed and the bed was tilted, leaving a tangible dent in the BuildTak surface. Then it moves to the second test point leaving a visible scratch on the surface. This is repeated for all test points with each nozzle and than the process failed.
I have lowered the bed and started active levelling again. This time the process went through, no compression of the cores spring, no tilting of the bed and the process finished successfully.
Thanks
Carsten