If your Z Endstop is not triggering this could be due to a manufacturer wiring configuration on your Z endstop connector. The EZABL board has been set up based on testing of multiple machines that we have in-house. But after sending out many kits it appears that the wiring that manufacturers use are not consistent and they reversed the wires in some Z Endstop connectors. This information is also covered in the EZABL kit installation guide.
EZABL Pro Kits
Just flip the Z endstop switch on the EZABL Pro Board to reverse the wiring. No swapping pins is needed on the EZABL Pro kits.
Once you change the switch position (EZABL Pro) re-run the M119 test. It should look like the screenshot below:
When the LEDs on the sensor and EZABL board are off z_min should show open. When the LEDs on the sensor and EZABL board are on z_min should show TRIGGERED.
Additional information about the use of the M119 command can be found here.