mcafee firewall not working as just downloaded OS big sure and now my Magee firewall is not working any help would be appreciated thanks guys

Just to add, if you have any other "security" apps installed you should uninstall those as well. They are not necessary, interfere with a Mac's built in security, and are known to cause various problems.

It may not be compatible with Big Sur. You should uninstall it anyway since it's not needed and macOS has a built in Firewall. As do most routers.

Uninstall McAfee. It is known to cause problems. (It also interferes with macOS' built-in security.)

It may not be compatible with macOS Big Sur.

(dialabrain beat me to it...)