1. Check if the issue is from publish server or dispatcher. If issue is from dispatcher then ensure that you have done required AEM dispatcher configuration
In dispatcher_vhost.conf file, set DispatcherPassError to ‘0’. This allows erring requests to be sent back to AEM.
2. Which AEM version you are using because on AEM 6.2 or above, this service uses a Service User for repository access. This user is configured with the expected permissions required, but additional permissions may be required if your repository design deviates from the expected structure. So please check if this user have proper permission on publish instance as well.