Public access downloading from bucket

Hello, I have given public access to everyone in an S3 bucket (it's a temporal thing and the only object is a simple file). However, and when I try to download the file (using an external account for testing) with:

$ aws s3 cp --no-sign-request s3://BUCKET/OBJECT /home/ubuntu

I'm still getting the error:

fatal error: An error occurred (403) when calling the HeadObject operation: Forbidden

In the permissions tab (for the bucket), it has Access: Public, Block all public access: Off, ACL Everyone (public access): List (Objects) and Read (Bucket ACL). I can list the bucket content but not make a copy. What else do I need to do to enable downloading the objects? Thanks.