It does download web installer exe’s just fine. (See Below)
Microsoft Edge Chromium, Version 90.0.818.42 (Official build) (64-bit), Firefox Version 88.0 (64-bit) both download all six links at this Avast site: https://forum.avast.com/?topic=260243.0
Turned off Anti-Phishing tool in ASB Settings but no joy.
Uninstalled ASB, reinstalled after removing reg keys related, no joy.
Changed the url for a full download to:https://files.avast.com/ and got this: https://www.avast.com/en-us/index#pc Download in ASB works but is, again, a web installer.
No notice of a block from Avast A/V or from ASB when this happens.