File name of the attachment removes the special character at the endpoint.
1. Create Action in integrationhub which sends existing Attachments to another attachment API
2. Request content has to be Multipart
3. Send Attachment to another service instance on /api/now/attachment/upload api
Ensure the Attachment has a non-ascii character:
Notice the special characters are replaced:
This problem is fixed in the next upcoming release. There is no workaround available. If you are able to upgrade, review the Fixed In section to determine the latest version with a permanent fix your instance can be upgraded to.