@dbro 

1. what is the current firmware version of your ER605 ?
2. is the error message you see a general error ?
3. there is a similar post here for your reference, I suggest you check to see if the ISP side is causing the problem.

https://community.tp-link.com/en/business/forum/topic/237140?page=6

@dbro I have about half of this same problem. I can run a speedtest successfully, but the results don't hang around across a reboot, and don't appear in the graph.

But the speed test results are terrible. I have symmetrical gigabit fiber, and the Speedtest client on my desktop happily reports 930/930 connecting through the ER605. The built-in speed test usually shows between 300-500 down, and about 800 up.

@Yannie 

Here is the info you requested:

ER605 Firmware  1.1.1 Build 20210723 Rel.64608

Yes, I am getting the general error as described in post #58: TL-R605 not visible in Dashboard and Speedtest loop - Business Community (tp-link.com)

My ER605 connected directly to my Motorola cable modem, which is connected Xfinity/Comcast.   I don't have a firewall in place that I control.

Is there a specific IP address or URL that the ER605 is using, that I could try to ping to see if I can access the site manually?

Dave

@dbro The default IP of the ER605 is 192.168.0.1