In 03.Archiving solution
If flat parameter for the fetch task is not set to true, it try to store file in
/backup/managed4-configuration.gz/managed4.example.com/backup instead of /backup/
from ansible-doc
flat: # Allows you to override the default behavior of appending hostname/path/to/file to the destination.
If `dest' ends with '/', it will use the basename of the source file, similar to the copy module.
This can be useful if working with a single host, or if retrieving files that are uniquely named per host. If using multiple hosts with the same filename, the file will be overwritten for each host.