Hello,
The possible cause is that the ONVIF configuration item is not enabled.
Please log in to the third party camera interface
In the camera interface, go to the settings and find out the ONVIF protocol
Once you found, choose to enable the ONVIF protocol.
After enable the protocol, you can set the ONVIF protocol settings which similar tothe photo I provided.
The ONVIF version should be clicked start from the lowest version to the highest version to see whether the VCN3010 can detect the third party camera or not.
Root Cause : Didn't enable the ONVIF protocol on third party camera
Solution : Enabled the ONVIF protocol

Thanks