Finally hired support since I was in a hurry. Seems that at some point the port set somewhere in Docker (don't ask me where exactly) was changed and was not anymore the one set also in CloudFront associated to the instance. This was discovered with the command: docker ps Which printed something like: 0.0.0.0:8081->8080/tcp, :::8081->8080 8081 was the value in the Docker configuration, but in CloudFront we had a 8080. I changed this last to 8081 too and now it works. Certainly the error messages were quite confusing.