For Connectify have you tried Internet Connection Sharing Mode ?

In addition to the above named ports, if your firewall software has any settings involving Internet Connection Sharing (ICS), please enable support for these.

Avast - Settings - Components - Firewall - Customise - Policies - and under “Preferences” select “Internet Connection Sharing mode” - OK.

https://forum.avast.com/index.php?topic=194021.msg1353407#msg1353407