DavidR
4
These settings don’t effect how avast works.
If downloading over an http connection then the web shield would be scanning that traffic (and may alert even before a file is completely finished downloading). If downloading over https it won’t be monitoring the traffic, but the fie system shield will be there as another line of defence for newly created files (which downloads would be).
So in the case of the https eicar test, depending on the file type (eicar.com file) that would be scanned, files that represent an immediate risk if infected would be scanned (executable files, etc.), .zip (archive) and inert files (.txt, etc.) wouldn’t be scanned on creation.
Unfortunately I can’t replicate your problem as I said my downloads complete without problem and I don’t have the browser.download.manager.skipWinSecurityPolicyChecks entry present and my browser.download.manager.scanWhenDone set to False. I also have what is in effect the default setting for Windows Internet Properties, Security Settings, Internet, Launching applications and unsafe files set to Prompt (images in my last post).