Intrusion & Line Crossing not working.

Hi All,

Wanting to try either Intrusion Detection or Line Crossing on my system to try & minimise the false triggers I get with normal motion detection.
Mostly Moths & Spiders.

Have followed all that I can find, even though the documentation doesn't quite match the firmware; but I just can't get it to detect.

Have drawn a region as well as a minimum size box & played with settings.
Get the impression I'm missing some other setting.

Hikvision NVR:-
Model# DS-7616NI-I2 / 16P
Serial#...

Intrusion & Line Crossing not working.