Can you post a video (youtube usually works best) of the attempting leveling process? Just seeing it from when it’s moving down to the silver Z minimum button to when it fails is enough.
Where is it hitting the Z minimum button? If it’s not in the center, just hit the power switch when it’s very close to touching so you can take an offset measurement. Here’s a quick diagram to show what the M206 command would be based on which quadrant of the button it’s hitting. Of course, use measured millimeters instead of the placeholder 2mm measurements in the diagram:
Once you send the M206 command in the terminal, you can send the M500 to save it to EEPROM. With it saved there, remove the M206 commands from your startup GCODE.
Be aware that running any old GCODE with an M206 will cause the machine to ignore your corrected M206 setting.