Ensure the printer is turned off and not plugged in.
While moving with the extruder, the X-axis motor works as a generator. You will create a small amount of electricity and the LCD might flicker. Move with the extruder reasonably slowly and in the future always use the printer's controls.
⬢Move the extruder manually all the way to the left.
⬢By rotating BOTH threaded rods at the same time on the Z-axis move the nozzle until you reach the heatbed. Try rotating both the rods equally!
Check again from a different angle the nozzle is touching slightly the heatbed. Don't bend the heatbed!
Don't place the steel sheet on the heatbed during the entire SuperPINDA sensor adjustment process. Wait for the XYZ calibration.