5500CN Ethernet LED flashing even without Ethernet cable plugged in

I recently moved into a new house that has a CBUS system installed. I'm the third owner, and I have no idea what the previous two owners did with the setup.

I’m trying to integrate the CBUS system with the internet so I can control it through Home Assistant or similar platforms. Fortunately, the system already includes a 5500CN module. But it looks like they didn't use it because the other end of the Ethernet cable isn't plugged into anything.

And the Ethernet LED on the 5500CN was flashing. I tested further and found that even after unplugging the Ethernet cable from the Ethernet port of 5500CN, the Ethernet LED continues to flash. Restarting the 5500CN didn't change this behavior either.

After I plugged the cable into the router, I used the ip utility and Lantronix device installer to scan for it, but they didn't find anything.

I have a few questions:

1. Could this indicate that my 5500CN is faulty?
2. Is it a straightforward process to replace the 5500CN with a 5500CN2?
3. Assuming it works, once I connect the 5500CN2 to a router, can I configure it to work with Home Assistant without needing additional hardware?

Thanks in advance for any guidance!