Spring security OAuth code flow - Invalid credentials

I am getting invalid credentials while implementing the Auth Code Flow with Oauth2 Spring Security. Below is the microservices flow:

Eureka Service - Gateway - Custom Spring Authentication Service - AM Service (pulls AM business data) - SM Service (pulls SM business data)

I am able to authenticate and auth code is getting generated as show below http://127.0.0.1:8060/login/oauth2/code/test-client?code=J5Qvmk&state=HLD0vIaz6GzJl4dK_HJCtt7CGojuPSBVj23bu9fL38s%3D

But then when trying to get redirected to original API call, it fails stating "Invalid credentials"

Below is the error: enter image description here

Below is the configurations on gateway:

spring:
  application:
    name: gateway-service
  cloud:
    gateway:
      default-filters:
        - TokenRelay
      routes:
        - id: CdsaiAMServiceApplication
          uri: http://127.0.0.1:8082
          predicates:
            - Path=/ams/**
          filters:
            - TokenRelay=
            - StripPrefix=0
            - name: Retry
              args:
                retries: 1
                statuses: UNAUTHORIZED
                methods: GET,POST,DELETE
                backoff:
                  firstBackoff: 10ms
                  maxBackoff: 50ms
                  factor: 2
                  basedOnPreviousValue: false
        - id: CdsaiSMServiceApplication
          uri: http://127.0.0.1:8866
          predicates:
            - Path=/sms/**
          filters:
            - TokenRelay=
            - StripPrefix=0
            - name: Retry
              args:
                retries: 1
                statuses: UNAUTHORIZED
                methods: GET,POST,DELETE
                backoff:
                  firstBackoff: 10ms
                  maxBackoff: 50ms
                  factor: 2
                  basedOnPreviousValue: false
      discovery:
        locator:
          enabled: true
  sleuth:
    sampler:
      probability: 1
  zipkin:
    baseUrl: ${ZIPKIN_BASE_URL:http://127.0.0.1:9411}

  security:
    oauth2:
      resource:
         user-info-uri: "http://127.0.0.1:8383/user"
      client:
        registration:
          test-client:
            provider: spring
            client-id: clientId
            client-secret: client-secret
            authorization-grant-type: authorization_code
            redirect-uri: '{baseUrl}/login/oauth2/code/{registrationId}'
            client-name: test-client
            user-info-authentication-method: header
        provider:
          spring:
            authorization-uri: "http://127.0.0.1:8383/oauth/authorize"
            token-uri: "http://127.0.0.1:8383/oauth/token"
            token-info-uri: "http://127.0.0.1:8383/oauth/check_token"
            user-name-attribute: preferred_username

Can someone please help.