Finally, I was able to publish my app to Production. However how many times I tried, I got the same error "Incorrect account information." when Resetting Password.
My sandbox app is working as expected. I also tried using current RingCentral password of production account which I always used to sign into https://service.ringcentral.com but then got an error when requesting a token
{
"error" : "invalid_grant",
"error_description" : "Invalid resource owner credentials",
"errors" : [ {
"errorCode" : "OAU-140",
"message" : "Invalid resource owner credentials"
} ]
}