Hello @Eastman03,

Can I know who is your ISP? Does it require any special setting parameters like VLAN ID? 

Please try the following procedures:

1. Power off both the ISP modem and the AX55;

2. Wait for 5 minutes;

3. Power on the ISP modem;

4. Wait for 5 minutes;

5. Power on the AX55 and connect it to the ISP modem LAN port;

6. Wait another 5 minutes, then check if the LED will turn green.

If still no internet on the AX55, but the internet still works fine on the old router, please try to clone the MAC address of the old router to the AX55 as follows, then check the internet again:

How do I configure MAC Address Clone on my TP-Link Archer Router? (Situation 2)

Hi  @Eastman03 

I was having this same problem on the AX50 a week after I changed my NBN RSP from Telstra to Aussie Broadband. I thought it was a dead router as I tried everything else. The PC could access the internet just fine when plugged directly into the NBN's DOCSIS modem, but when I connected the HFC docsis modem to the router's wan port with the same cable I'd get an orange WAN light on the AX50 and no internet throughput. The AX50 control panel said it wasn't connected to the WAN. So I assumed the AX50 was busted and I purchased a new AX55, and had exactly the same issue!!!

After watching the TP-Link support vids, I cloned my PC MAC (that worked into the RSP's DOCSIS modem) into the AX55, restarted the system (5 min power down on the DOCSIS modem AND the router), and it all worked just fine for me after that. Cost me $200 for the new router to figure this out! Not happy, but at least the AX55 gains me mesh capability that I didn't have in the AX50.

Dunno if this will help the OP, but it worked for me.

P.S.: Also the AX55 has had two firmware updates in two days after getting it connected. I now have a firmware level more recent than the one shown in the firmware download page. Go figure?...