I don’t know, I assume both should work. Which S3 provider do you use?
Unfortunately I have no S3 to try. Is there a good free (without need for credit card data) S3 service?
If it’s ok for you, PM me your S3 login so I can try and maybe find out what’s going on.
From the docs it should be compatible with others:
Amazon S3 (Cloud Object Storage - Amazon S3 - AWS) compatible (like https://www.minio.io/).
EDIT:
We managed using the S3 server via CLI and that worked. So the cockpit check seems to have some problems with S3.
http://docs.nethserver.org/projects/nethserver-devel/en/latest/nethserver-backup-data.html#s3
We got the same error with working credentials:
