Hi. I'm David, and I'm happy to help you.

Please clarify the following:

• Do other devices on the same network also fail to reach these sites?
• See if the same behavior occurs in an InPrivate window. To open the InPrivate window, open the browser and press "Ctrl + Shift + N".
• Can you test to see if the websites open in another browser?
• Do you have any VPN software installed? (Even if it's not running at the moment) If yes, which one?

Looking forward to your reply.

ERR_CONNECTION_TIMED_OUT usually indicates a network or TLS/HTTPS connectivity problem rather than an issue with the specific site being “insecure.” For Microsoft Edge on Windows 10, use these steps to isolate and fix it:

1. Test basic connectivity
   • Try opening several well-known sites (for example, a major search engine) in Edge.
   • If all sites fail, there is likely a general network or DNS issue (Wi‑Fi/router/ISP or VPN/proxy). Restart the router and PC, and temporarily disconnect from VPN or proxy if used.
2. Check if security software or filtering is blocking the sites
   • If using any web security/filtering (for example, corporate security agents, parental controls, or secure web gateways), they can cause generic browser errors like This site isn’t secure, There’s no internet connection, or connection resets when traffic is blocked.
   • If Global Secure Access / Defender for Cloud Apps or similar is in use, verify that the sites are not being blocked by policy and that required outbound connectivity is allowed.
   • In that case, an admin should:
     1. Ensure outbound port 443 is allowed to the required Azure IPs/DNS names for the security service.
     2. Confirm that the client is correctly onboarded and that the traffic logs show whether the destination is blocked or allowed.
3. Verify TLS settings in Windows/Edge
   • Some network/security services and modern sites require TLS 1.2. If TLS 1.2 is disabled, or if only TLS 1.2 is enabled but the remote endpoint does not correctly negotiate, connections can fail.
   • On Windows 10 (affects Edge, Chrome, and IE because they share system TLS settings):
     1. Open Internet Options (search for it from the Start menu).
     2. Go to the Advanced tab.
     3. Under Security, ensure TLS 1.2 is selected (enabled).
     4. Select Apply, then OK, and restart Edge.
   • If using older environments or compatibility scenarios, some guidance also recommends ensuring Use TLS 1.0 is selected for legacy services. This is only for troubleshooting and may reduce security; prefer TLS 1.2 where possible.
4. Check for browser/network misconfiguration
   • In corporate or filtered environments, misconfigured firewalls or proxies can cause generic errors like This page can’t be displayed or This site isn’t secure.
   • Ensure the firewall is configured to allow HTTPS (port 443) to the required destinations and any security service endpoints.
   • After changes, restart the device and Edge and test again.
5. Try a clean browser profile
   • Sign out of all Microsoft accounts in the browser.
   • Clear all site data/cookies for the affected domains.
   • Test again in an InPrivate window.

If the issue persists only for specific domains (like the training host and Zoom) while other HTTPS sites work, it is most likely due to:

• A network/security product blocking or intercepting those specific domains, or
• TLS negotiation issues between the client and those servers, which can often be mitigated by ensuring TLS 1.2 is enabled and network rules are correct.

References:

• Troubleshooting access and session controls for admin users
• Troubleshooting guide for Internet Explorer when you access Microsoft 365, Azure, or Intune
• Some HTTPS websites cannot be displayed in Internet Explorer 9 or Internet Explorer 10