The camera setup we use relies on ONVIF for discovery, which is handled by two bits of software. rpcd-mod-onvif on the receiving device to carry out WS-Discoveries and various ONVIF control functions, and camera-mod-onvif on the camera device side to respond. Here’s a bit of an informal diagram:
There are a few reasons this might fail:
- either rpcd-mod-onvif is sending ONVIF out the wrong interface;
- camera-onvif-server isn’t listening on the correct interface;
- /dev/video0 on the camera device has not come up - which camera are you using? You may need an additional driver
On the camera side, what is the output of logread | grep camera-onvif-server.
On the viewing side, what interface is it configured for in the WebUI?
Yes, but let’s try some debugging first 
You can plug the dongle into a Raspberry Pi. The steps as followed in Build Thread: HaLow for Raspberry Pi OS will be largely the same, except for USB you won’t need to worry about device tree.