Forwarding logs to New Relic // License key has wrong format

Hello everyone,

I am currently trying, as described in https://developer.adobe.com/app-builder/docs/guides/application_logging/new_relic/, to forward my logs to New Relic.

However, I keep getting an error that my license key has the wrong format. I checked the license for the string length as well as for invisible characters and spaces, but found no errors.

When I try it with Postman, it works fine with the used "INGEST-LICENSE"-Key, and I can see the logs in New Relic. 

Is there a known workaround to fix this problem?

Thanks