Hey Guys,
same problem here:
First things first; long time → no problems, best printer in the world 
But out of nowhere:
1. fails to pass the bed level process several times
2. the bed leveling process lasts so long…
Error Message Point 1:
(German) Druckbettkalibration fehlgeschlagen [0300 4002 225611]
[translatet] print bed calibration failed [0300 4002 225611]
Problem spots Point 2:
The problem spots for Point 2 are the back left and back right side of the print bed, where only one pressure sensor is in the middle.
The bed hits 21 times against the nozzle (on the same spot), the bed drives away, wobbles, and starts again on the same spot.
If this process fails 4-5 times, the whole calibration fails with the error message described above.
The normal amount of samples per point is 3 (the nozzle touches the build plate 3 times).
In my point of view it has to do something with temperature over time:
When my printer is cold (e.g. one day no printing) and i want to print something the bed leveling process always pass.
BUT
the colder the bed temperature is, the less samples per point it takes (only for the first print job)
35 deg cel = 3-4 times (all over the plate)
55 deg cel = 3-4 times in the front area and the middle / 8-15 times on the rear left/right
70 -100 deg cel = 3-4 times in the front area and the middle / 10-21 times (and 2-3 times the process described above, on especially the left and right rear sides)
If the print is done and i try to print something afterwards (with the bed leveling, e.g. other material), it gets worse and fails a lot.
The support send me a new print bed → no improvement
I dont know why the sensors didn’t get the height of the print bed, when the nozzle touches the build plate so often…
and i want to understand this.
But at this point, the support doesn’t answer me.
Greetings Guys
and Happy Printing