spring security reactive "Invalid credentials" error using Cloud Foundry UAA

Question

I want to authenticate users with Cloud Foundry UAA provider in my reactive spring boot application.

Following to this tutorial I can get token using Tomcat, when my app is not reactive. But I'm getting error with Netty, using starter-webflux. Configuration and screenshots are below.

spring:
  application:
    name: Authorization App
  profiles:
    active: dev
  security:
    oauth2:
      client:
        provider:
          uaa:
            issuer-uri: http://localhost:8080/uaa/oauth/token
            user-info-uri: http://localhost:8080/uaa/userinfo
        registration:
          uaa:
            client-id: webappclient
            client-secret: webappclientsecret
            scope: resource.read,resource.write,openid,profile
            provider: uaa
            redirect-uri: http://localhost:8081/login/oauth2/code/uaa
            authorization-grant-type: authorization_code

After successful login, authorization and setting up scope through UAA my redirect page, where token should be, looks like:

Invalid Credentials error screenshot

And I can't find any error description or logs

Web console screenshot

What could be issue?