Although it is still not clear to me which firewall you are using, please follow the following:

Avast main GUI → troubleshooting → “load avast service only after other system services”. Save that setting.

Now go to your firewall and delete all the rules (inbound, outbound, all network connections) that are somehow related to Avast and to your web browsers.

Then reboot. Don’t force the updates. Wait at least 10 minutes after the reboot. If your firewall asks, let Avast connect. Only then open Avast main GUI → maintenance → update. Do not try to manually update yet. Post here the results shown in that tab.

In addition, check your firewall logs AFTER the above instructions are completely followed.