Jtdylktuy

Overview:

I'm getting an ERR_CONNNECTION_CLOSED when trying to access specific websites over https. This seems a fairly common issue, but I haven't been able to find anything quite like what's happening to me. I'm using a brand new Dell XPS laptop with Windows 10, build 17134.

Here's a quick summary, with more detail below:

• The issue is isolated to the combination of laptop + one wifi network. Other Win 10 PCs on same network work. The laptop on another network works too.


• The issue is not browser specific, and isn't fixed using incognito


• A factory reset has not helped


• Restarting the router has not helped


• Setting a proxy using mitmproxy, websites all load fine

Details:

The first sign of problems was that Windows wouldn't activate as it couldn't reach the activation server. I then followed a link to a microsoft help page using Microsoft's Edge browser and got this ERR_CONNNECTION_CLOSED error back.

I've since tried:

Connecting using a different wifi network. I've tried 4 different wifi networks; they all work fine except my home wifi (TPLink Archer VR2600 on BT Infinity VDSL, both 2.4GHz and 5GHz networks). I activated windows, ran a full update etc whilst connected to a working network.

Uninstalling McAfee software and disabling windows defender and firewall

Chrome, Chrome in incognito mode, Edge, Firefox and Opera - all browsers display the same behaviour.

Different https sites - some are fine (Various google sites, bbc.co.uk, github, superuser.com and loads more), others are not (netflix.com, microsoft.com, mozilla.org, itv player (website is ok but player is not))

Rebooted the router

Using mitmproxy to view the messages. As soon as I put mitmproxy in the middle - everything works fine. I'm sure there's a clue here but I don't know what it means! Other https proxies work too.

I installed git and using git bash ran curl https://www.mozilla.org/en-GB/. This worked fine, but the site won't load in a browser

I ran a factory reset - the same issue persists

I've tested with my desktop PC (windows 10, same build 17134) on the same networks and it has no problems at all, nor does a Windows 8 laptop.

I ran a client ssl/tls capabilities check on ssllabs.com and this came back good, though did flag up that TLS 1.0 is enabled along with some weak cipher suites.

I ran malwarebytes anti-malware and it came back clean

I suspect there's some Windows level setting causing this, though I don't understand why it would work on other wifi networks. I'm really at a blank as to where to go next with it, so hope someone can help!