It seems ever since my laptop updated to Windows 11, I get this error for trying to access Costco or Lego.

I had this issue for over a week. I called my network company Eero, spent an hour on the phone with them, but they were not able to resolve it. I had asked them about changing the IP but I am not sure if they actually did. They suggested I call my service provider. I spent 30 minutes on the phone with them, once again did the whole thing of factory resets, powered down modem and router for 5 minutes, none of these things worked. They said they would send out a tech. The tech came today, tried several things like updating some of the hardware outside, that didn't work. In the end, they did another complete power down, REPLACED THE ETHERNET CORD BETWEEN THE ROUTER AND MODEM, and that worked. I again have access to all of the sites. 🤷‍♀️

My problem got resolved. I have a cable modem and a separate Deco X20 Mesh wifi router. The xfinity tech plugged his computer directly to the cable modem and he was able to access the sites I've been having problems with. I then used the MAC Clone capability of the Deco to set a new MAC address. After rebooting and powering off and on the Deco, things started working again.

I would assume if I changed the public WAN IP, my issue would go away, at least temporarily get removed from the blacklists.

But my Deco doesn't seem to have a way to change its MAC address :-(

I think if I leave the unit off for long enough, it will lose its IP and my ISP will probably assign a different IP so I may try that.

With Deco, one thing I thought of is I could have switched which Deco was the main Deco. That way you would get a different IP address. I didn't do this, but I think it would have worked.

Xfinity (aka Comcast) told me I would have to leave it off for 4 days to release the IP Address. I had left it off for 24 hours and that didn't work.

Holy **** you're brilliant! I didn't even think of swapping which unit was the main unit!

Going to try it within the next few days!