We have set up a S3 bucket with CORS rules to upload data to. The upload is done using a presigned URL and a multipart upload. We have several deployments that have this setup working. On the latest setup that we deployed today the S3 bucket is returning a HTTP code 500 (in the OPTIONS request) and a CORS error No 'Access-Control-Allow-Origin' header is present on the requested resource when attempting a PUT request using the needed payload and headers.
While investigating the error with curl we found that the bucket returns a redirect from https://bucketname.s3.amazonaws.com/ to https://bucketname.s3.eu-central-1.amazonaws.com/. When we send a request to the URL that includes the region with the needed payload and headers, we now receive Access-Control-Allow-Origin headers but a HTTP code 403 with a response that the signatures do not match.
When the CORS configuration is removed from the bucket, we receive HTTP code 403 and a CORS error.
We have also tried server different options in the CORS configuration, all of which resulted in a HTTP code 500.
Rebuilding the bucket also did not change the above-described problems.
