Metadata for entity and role {urn:oasis:names:tc:SAML:2.0:metadata}IDPSSODescriptor wasn't found

Hi all,
I am new to this SAML and okta stuff. I have implemented the sprin-security-saml2-sample successfully with SSOCircle and was trying to do the same with okta but failed.
error i am seeing is:
Metadata for entity https://dev-997261.okta.com/app/argodev997261_amloasis_2/exk25z0mk2GK604kR357/sso/saml and role {urn:oasis:names:tc:SAML:2.0:metadata}IDPSSODescriptor wasn’t found

Here’s teh relevant entries from mt securityContext.xml

<bean id="metadataGeneratorFilter" class="org.springframework.security.saml.metadata.MetadataGeneratorFilter">
    <constructor-arg>
        <bean class="org.springframework.security.saml.metadata.MetadataGenerator">
            <!--property name="entityId" value="saml-federation.appspot.com"/-->
            <property name="includeDiscoveryExtension" value="true"/>
            <property name="entityId" value="oasis-login.argodata.com"/>
            <property name="extendedMetadata">
                <bean class="org.springframework.security.saml.metadata.ExtendedMetadata">
                    <property name="signMetadata" value="false"/>
                    <!--property name="idpDiscoveryEnabled" value="true"/-->
                </bean>
            </property>
        </bean>
    </constructor-arg>
</bean>

<!-- IDP Metadata configuration - paths to metadata of IDPs in circle of trust is here -->
<bean id="metadata" class="org.springframework.security.saml.metadata.CachingMetadataManager">
    <constructor-arg>
        <list>
            <!--SSO CIRClE-->
            <!--bean class="org.opensaml.saml2.metadata.provider.HTTPMetadataProvider">
                <constructor-arg>
                    <value type="java.lang.String">https://idp.ssocircle.com/idp-meta.xml</value>
                </constructor-arg>
                <constructor-arg>
                    <value type="int">5000</value>
                </constructor-arg>
                <property name="parserPool" ref="parserPool"/>
            </bean-->
            <!--OKTA-->
            <bean class="org.opensaml.saml2.metadata.provider.HTTPMetadataProvider">
                <constructor-arg>
                    <value type="java.lang.String">https://dev-997261.okta.com/app/exk25z0mk2GK604kR357/sso/saml/metadata</value>
                </constructor-arg>
                <constructor-arg>
                    <value type="int">5000</value>
                </constructor-arg>
                <property name="parserPool" ref="parserPool"/>
            </bean>

        </list>
    </constructor-arg>
    <property name="defaultIDP" value="https://dev-997261.okta.com/app/argodev997261_amloasis_2/exk25z0mk2GK604kR357/sso/saml"/>
</bean>

A similar topc was opened in Jul by @pradeep.burugula but remained unanswered.

Any help is appreciated.