Hello, there are many many reportings ogf this issue on Avast Forum but I did not find the solution.
I have a Windows 10 PC with Avast Internet Security which shares its internet Connection (Bridge/Hotspot). There is a Ethernet connection between my router and PC, and a wifi connection between my PC and other home devices.
Avast blocks devices to connect. When I disable Avast Antivirus, than other devices connect fine.
I have tried to work with the "System" and "svchost" firewall rules but did not manage to get it working. Any help would be appreciated.