As the response status is 200, but the type is CORS, could it be that storj doesn’t include “ETag” in the “CORS-safelisted response-header name” (https://fetch.spec.whatwg.org/#cors-safelisted-response-header-name).
Here is a stack overflow thread showing how this would be done on the server side: json - How to fix this error I’m getting from Amazon s3: ETagMissing: No access to ETag property on response. Check CORS configuration to expose ETag header - Stack Overflow