BLtouch + Creality 427 on Ender 5

Maybe you can extract some information here:

Unfortunately the user @DaveWW00 did not report back on how he solved it.

Two additional comments:

[stepper_z]
...
position_min: -1.5

You should give the BLTouch a bit headroom in the Z-direction

[bltouch]
sensor_pin: ^PA7
control_pin: PB0
x_offset: -37
y_offset: -12
z_offset: 0
samples: 2
pin_up_reports_not_triggered: False

Remove the z_offset. This is set via calibrating-probe-z-offset