I/O exception (java.net.SocketException) .....https://dev-XXXXX.okta.com:443: Connection reset

Hi,
I am new to integrating Okta with Spring boot. I am trying to implement exactly the Spring Okta Integration as documented on https://www.baeldung.com/spring-security-okta.

When I invoke my rest api http://localhost:8080/users, I get error
2022-01-26 15:42:10.202 INFO 25208 — [nio-8080-exec-4] o.apache.http.impl.execchain.RetryExec : I/O exception (java.net.SocketException) caught when processing request to {s}->https://dev-XXXXX.okta.com:443: Connection reset
2022-01-26 15:42:10.202 INFO 25208 — [nio-8080-exec-4] o.apache.http.impl.execchain.RetryExec : Retrying request to {s}->https://dev-XXXXX.okta.com:443

If there was a firewall issue, I would not be able to execute different type of postman okta sample collection to my dev tenant correct? What am I missing?