New Hikvision Cameras - On Camera Motion / Line Crossing Not Triggering Channel Record on NON Hikvision NVR?

[ipni]

I have a client who paid a lot of $$ for a 24 camera and NVR system.

The cameras are a mixed bag of models:
ENC304
DFI64162
NC304
The NVR is a Galaxy Hunter 32 channel, up to 4k

We are upgrading the cameras on this system (New Hikvision 4k PCI-LB18F4S2 + DS-2CD2383G2) and will eventually replace the NVR with a matched Hikvision NVR. We're trying to space this out so the cost is spread out over time.

Since the Hikvision cameras are new and have advanced motion detection and can actually classify human/vehicles, we have these smart events analyzed on the cameras and they send out email alerts and images.

For some reason the cameras aren't triggering the NVR to record the actual event detections.
I assumed any on-camera event would push a bit/alert to the NVR to record the event video, but this is not happening.

I know it should all be Hikvision and everything will work, but is there a trick to get a Hikvision camera to trigger recording on an ""off brand" NVR for On Camera smart events?

This seems to work find with the 3 old camera models.
Thanks