In the log of the download I cannot find a deviation:
{“reqId”:“XXXXXXXXXXXXXXXXXX”,“level”:1,“time”:“2018-08-15T19:25:45+00:00”,“remoteAddr”:“79.203.36.80”,“user”:“NAME”,“app”:“admin_audit”,“method”:“GET”,“url”:"/nextcloud/remote.php/webdav/temp/bilder.zip",“message”:“File accessed: “/temp/bilder_kindergeb.zip””,“userAgent”:“Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:61.0) Gecko/20100101 Firefox/61.0”,“version”:“13.0.5.2”}