i dont have avast >:)

b 2 uses network protocols udp and https. Perhaps avast (firewall?) blocks them? See https://support.avast.com/en-in/article/Antivirus-Firewall-Application-Rules , you would have to set Application Rules to allow 5 bars for "X:\YOURPROGRAMS\Steam\steamapps\common\b 2\b 2.exe", X being the letter of the drive you installed Steam on and YOURPROGRAMS being your programs folder (if any) like "Program Files". b 2 has outgoing and incoming connections to and from the content and multiplayer server only and wouldn't require "all internet access" but I didn't see a more granular setting in above avast documentation.