Invalid auth token

We are having an issue while creating a meeting with Zoom.
We get this error:
Failed due to error: Fetching tokens failed with error: {"reason"=>"Invalid Token!", "error"=>"invalid_grant"}"

When checking about this in devforum, came across this issue Frequently receiving invalid_request / token revocation from Zoom - #12 by will.zoom, were it was suggested that Zoom will work to allow simultaneously use multiple access tokens, Is this done? I still see errors related to multiple sign ups

@Rithanya , do you have a code sample?

Do note that in the oauth 2.0 flow, the ?code in the redirect query string can only be used once.

More info: This issue is raised when we try to refresh the access token with the existing refresh token. The refresh token is invalidated somehow.
@chunsiong.zoom , can you share a mailid to share the code samples?

@Rithanya , what language are you using?

We are using Ruby @chunsiong.zoom

Are you getting the new access token and refresh token the first time the refresh token is used or is the refresh token not working at all?

@Rithanya I do not have a sample code in ruby, but I do have them in php, python and nodejs. Would any of these help? Let me know and I can share it here