Being able to access that page is good as it means nothing is blocking it. Some countries block it. Or you IP address could be on a black-list somewhere.
I think you need to check the status of the device on the router. That tells more about what is happening. From here, I can't tell if the device is not connecting to WiFi or something is happening further down the track.
Manually installing newer firmware might help. There have been some changes in how not being able to fetch the above page works. The change means that the WiFi can be kept up when the page cannot be retrieved. That is for the case where someone wants to use the WiFi locally or within a firewall blocking access. But, I'm not sure what happens if that occurs during the setup.
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