I've had the BLTouch working fine using this kit and following the instructions it shipped with.
I wanted to increase the number of probe points so I've attempting flashing with Marlin to achieve this. With the home-brew Marlin the probe doesn't extend for homing, with the default Creality firmware.
I'm running an Ender 3 Pro on 4.2.2 Mainboard. The wiring diagram has used the Z endstop connector for the BLTouch, I've followed this video, but clearly the wiring mechanic is different.
// Force the use of the probe for Z-axis homing #define USE_PROBE_FOR_Z_HOMING
But it has no effect. x and y work fine, but at z the probe doesn't extend.
Since it boils down to some setting changes in the firmware (since that's the only thing that has changed) I'm hoping someone has the answer to this question already. Unfortunately, I can't find any Creality source code for comparison and since it is working on their firmware and not the home-brew my expectation is I've missed a setting.