I am attempting to set up a C7 via an Asus Blue Cave. I am using the "central" Blue Cave (I have more set up as an AI mesh). The hub indicator is green but the phone app does not detect it and a webpage (using a computer also connected by ethernet to the same Blue Cave) will not detect it. For the desktop I am using Chrome and find.hubitat.com but it just keeps cycling.
Lot of things we can try here. Let’s start by looking at the router’s attached devices screen. Another place to look is to get to a command prompt on the PC and type in arp -a - this will generate a list of connected MAC address and associated IPs (hub’s MAC is on the bottom of the hub). Still not finding it, try rebooting the router and retrying the find from the phone app and webpage. Finally, there’s a small button underneath the hub that will force a reset of the DHCP settings on the hub (after which reboot the hub and try the find actions again.)
I don't recall off the top of my head but the find.hubitat.com may not work across subnets. If you have more than one VLAN setup you might try switching your computer to each VLAN and run the search.
On a slightly related note I did have trouble setting the C7 up with a static address on a different VLAN. It took lots of reboots and configuration fiddling but that might be related to the Ubitquiti equipment as well.