Keycloak Instance not created using keycloak-js

This could be very simple issue but right now unable to proceed.

Keycloak (14.0) is configured for React+Typescript application and use of PKCE.
This set-up worked well when POC was carried out two months back.
But, now it’s not working even with Keycloak 16.1.1 version.
No instance of Keycloak is returned by the call to Keycloak(keycloakConfig)
‘keycloak-js’ version always kept in sync with server version.

const keycloakConfig = {
    url: '',
    realm: 'my-realm',
    clientId: 'my-react-app'

const keycloak = Keycloak(keycloakConfig);
console.log('keycloak ==>' + JSON.stringify(keycloak));

Above code now logs output as: keycloak ==>{}
Already spent a full day to solve the issue which might be small but unable to do so.
Any pointers to overcome the issue are appreciated.