Most troubleshooting issues can be resolved by upgrading the ORCID plugin. If you run into any issues, try upgrading the plugin first. You should also check periodically to make sure your ORCID plugin remains up to date.
To update the plugin:
Ensure that your ORCID plugin is actually configured and not just enabled; don’t enable it unless you are ready to configure it.
Check to ensure that authors are using the current link and not a previous link from the sandbox. If you are on OJS 3.2 it may also be this bug in ORCID email template for authors - https://github.com/pkp/orcidProfile/issues/122 (which is resolved in 3.2-1-3 and 3.3)
Redirect URIs are used by ORCID’s authentication service as a security measure. This prevents services from impersonating each other. You must register all redirect URIs: see instructions to update or request new redirect URI(s).