Big Sur & Firewalls
I have to assume others have ran into this issue where the new 3rd party firewalls setup with Big Sur has caused headaches. Â I've tried McAfee, Intego and these firewalls create some kind of network extension and that appears to operate as the firewall. Â However, this setup kills my internet access on my virtual machines through parallels. Â Both Windows 10 and Ubuntu lose internet access unless I go into the MacOS Network Preferences and disabled the network extension the firewall creates....thus basically turning the firewall off. Â Â Link to post
Source: neowin.net