Since you've provided little detail as to HOW it's "not working", this is only a guess, but the author found it worthy of special mention:
Gatekeeper in macOS X 15 Sequoia
Since you've provided little detail as to HOW it's "not working", this is only a guess, but the author found it worthy of special mention:
The Beta key has expired & I guess you missed Test to see if people READ MESSAGES before posting ?