There is a widespread bug in some Windows 10 and Windows 11 systems that may cause you to have problems connecting to certain websites or you may have problems with websites not working properly.

If you have a system with an Intel Ethernet and/or Wi-Fi device that is branded as "Killer(R)", you may have the problem. If so, a service is installed in Windows that you can't uninstall nor update to a version that fixes the bug.

To fix the problem, run services.msc and that brings up the Windows Services window. Find "Killer Network Services" in the list and right click on it, then choose "Stop." If you right click on it again, you can click "Properties" where you can set the startup type to "Manual" or "Disabled". This will keep it from starting when you start Windows.

This service causes problems with and websites. There are probably many other sites, but if you get a messages from your browser that says it can't connect to sites, even if it is infrequent, this could be the cause.

It will also cause sites not to work properly and prevent login forms from working because of being blocked.

If you update your Killer Wi-Fi/Ethernet drivers, the service may be enabled again and continue to give you problems. 

You can see more about stopping the service under the "(Optional)" section here: