hasAuthority() with Okta bearer token for Spring Cloud Gateway

I am having multiple downstream services to which I am routing via a spring cloud gateway service which also has okta auth. Currently I am able to route authenticate users at the gateway and return 401 for all requests without a valid bearer token. However when I try to implement role based auth, i.e. GET requests can be sent downstream for everyone group, but POST requests require ‘admin’ group membership in okta. This does not work as any authenticated user is currently able to make post requests. I have added claims to the access/id tokens and checked them in the Token preview section of my default Authorisation server in okta. following is my security configuration.

public class SecurityConfiguration extends WebSecurityConfigurerAdapter{
    protected void configure(HttpSecurity http) throws Exception {
            .authorizeRequests(authorizeRequests -> authorizeRequests

Due to only the gateway having okta auth and downstream services being protected by api token, I cannot implement preAuthorize and have to rely on httpsecurity, but I seem to be missing something