All supported DevTest releases.
During investigation of the issue, it was found that there were multiple other services running on same PORT with different base paths with HTTP protocol.
Since this service was using the same PORT but was configured to use SSL/HTTPS, it was not able to pick up the relevant changes of SSL and responded from HTTP call as other services.
The basic resolution of this issue is to use a different PORT for HTTP and HTTPS calls.
Multiple services can use same port with different base paths only if they are using same protocol - either HTTP or HTTPS.