As discovered in comments to JENKINS-54556, a JavaScript problem prevents authorizationMatrix from working in the declarative options generator.

Likely related to the other JavaScript problems.

TypeError: master is null 

 Probably due to https://github.com/jenkinsci/matrix-auth-plugin/blob/2be2070e8023219c2b8d70e8e09be1dd757c2702/src/main/resources/hudson/security/GlobalMatrixAuthorizationStrategy/config.jelly#L144

Would not be surprised if this ends up being the same problem as JENKINS-47697 and JENKINS-47885, as in all cases, IIRC, the problem is the insertion of a matrix-auth configuration that wasn't in the DOM already when the page loaded.