[Visual Studio] No Connection to Online <New Item> Template

The fact that NuGet and other network services are working doesn't necessarily mean Visual Studio can reach the service used by the Online templates. Visual Studio makes separate network requests for different features, so it's possible for one to work while another is blocked or failing. Microsoft also notes that partial feature failures can be caused by IPv6, proxy, firewall, or other network configuration issues.

I would try these checks:

1. Test the connection outside Visual Studio. Open Command Prompt and try:

curl -v https://marketplace.visualstudio.com

If this fails or hangs, the problem is most likely network/proxy/firewall related rather than the template itself.

2. Check Visual Studio's proxy settings. Visual Studio normally uses the Windows proxy configuration. In newer Visual Studio versions, you can check:

"Tools → Options → Proxy Configuration"

Make sure you're not using an incorrect proxy configuration. Microsoft documents this behavior here:

https://learn.microsoft.com/en-us/visualstudio/ide/reference/proxy-settings

3. Try another network, preferably a phone hotspot. If the Online tab works on another network, that would strongly point to the current network, DNS, proxy, firewall, or ISP configuration.
4. Don't rely only on ping. A successful IPv6 ping only shows that ICMP connectivity to that address works. It doesn't prove that the HTTPS request Visual Studio needs is succeeding on port 443.
5. Check Visual Studio's network/proxy troubleshooting information if the problem persists. Microsoft specifically recommends testing the affected resource with "curl" because it helps determine whether the failure is outside Visual Studio itself: https://learn.microsoft.com/en-us/troublestroubleshoot-network-related-errors

As a workaround, if you already know the template you need, you can also install a template/extension from a downloaded package when available instead of relying on the Online tab.

Since your screenshot shows the Online tab staying on "Retrieving information..." and eventually reporting that online browsing is unavailable, I'd start with the "curl" test and a different network. Those two tests should quickly tell you whether you're dealing with Visual Studio itself or the network path to the Visual Studio Marketplace.