can you take a photo of your sensor pcb, you need to confirm your sensor power supply voltage.
usually Vcc is dc12v, connect 12v and GND to sensor, then sensor's "output" and GND connect to KC868-A16's digital input port and GND.
I have hcr501 pir sensor it works with 5 to 12 v dc..
I tried hard but output is stuck.
My wiring is correct as you mentioned above.
Can you please try this sensor with your a16 board and check it.??