We put our releases to s3, and have cloudfront configured. Most likely it hasn’t been invalidated yet. Could you post output of the following command?
$ curl -I http://packages.couchbase.com/ubuntu/dists/trusty/trusty/main/binary-amd64/Packages
HTTP/1.1 200 OK
Content-Type: binary/octet-stream
Content-Length: 5033
Connection: keep-alive
Date: Wed, 12 Jul 2017 18:09:28 GMT
Last-Modified: Wed, 12 Jul 2017 09:29:28 GMT
ETag: "217ce5fd420630a7526e0a95839afee2"
x-amz-version-id: 2ITjvXvgSikfrC_j87VYfqW9tjYhJ_qG
Accept-Ranges: bytes
Server: AmazonS3
X-Cache: Miss from cloudfront
Via: 1.1 2d1245882c0beb52d08e23e1fa6ab592.cloudfront.net (CloudFront)
X-Amz-Cf-Id: nPTBcgVpXuKVs1tJxYE5qvQPEplu1hXOck_fAuHfI_dins4Sz3Pj-A==