Welcome to the forum!
Has the Z axis / sensor probe worked before? Or has it never worked?
If you haven’t already, you should check that all connectors are connected properly - at both ends of the cables.
It did work before. It seems to have stopped working shortly after I changed out the nozzle for a Hardened Steel version. I did all the bed leveling and Z axis adjustments and things were going OK, (but I was having some trouble with bed adhesion, probably due to the Hardened Steel Nozzle).
At some point, the nozzle dragged across the bed and gouged the plate. Shortly thereafter I had the problem where the probe started digging into the bed at start up.
I decided to remove the extruder and check the connections and placement of the sensor. I realized that the blue tip of the sensor wasn’t sticking out as far as it used to… After playing with it a little I was able to push it back down into the cylindrical holder. This seems to have solved the problem.