Ender 5 Plus - does not level, the Z axis goes down, always
I had the same problem with my Ender 5 Plus.
There is a small set screw at the top of the BLTouch you will need to tighten this in to adjust the location of the sensor pin. Keep screwing it more and more until you see it initialize reliably that is it should move out and back twice to initialize.
When the BLTouch initializes correctly then the leveling can be completed.