Just go to Avast, Menu, Configuration, Scam Protection (really a Web Shield), Deactivate the first option: HTTPS Analisys. It breaks many webs and 2FA, and it is not necesary at all. It should be deactivated by default. Just test it with any Web that seems unstable or hanged. Mine were all fixed by this simple tweak. 
First, the Scam ‘Guardian’ is now a collection of functions, the Web Guard, the Email Guard and Avast Assistant.
Deactivation the HTTPS scan is the proverbial throwing the baby out with the bath water. Most sites are HTTPS and disabling it leaves you wide open to Exploit.
In the WEB Guard settings there is the Option not to enable the QUIC/HTTP3 as some sites aren’t able to handle this is relatively new and some sites can’t handle it. I would suggest you try that option first, before disabling main HTTPS function.
Your system your choice, but to offer it as a fix for everyone isn’t wise.
1 Like