Late answer, but with Azure blobs (I know you asked about AWS, but this drove me crazy trying to figure out so answering anyway) you have to set Accept-Ranges specifically as an Allowed Header, just setting it to *
doesn't work.
I used the following C# code to do this:
var url = new Uri(String.Format("https://yourblob.blob.core.windows.net"));
var credentials = new StorageCredentials("accountname", "key");
var client = new CloudBlobClient(url, credentials);
var corsRule = new CorsRule();
corsRule.ExposedHeaders.Add("Accept-Ranges");
corsRule.ExposedHeaders.Add("Content-Encoding");
corsRule.ExposedHeaders.Add("Content-Length");
corsRule.ExposedHeaders.Add("Content-Type");
corsRule.AllowedHeaders.Add("Accept-Ranges");
corsRule.AllowedHeaders.Add("Content-Encoding");
corsRule.AllowedHeaders.Add("Content-Length");
corsRule.AllowedHeaders.Add("Content-Type");
var serviceProperties = CloudBlobClient.GetServiceProperties();
serviceProperties.Cors.CorsRules.Clear();
serviceProperties.Cors.CorsRules.Add(corsRule);
client.SetServiceProperties(serviceProperties);