In the Copy URL menu for files stored in AWS S3, the Pre-signed URL values contain the bucket name twice in the subdomain field. E.g. if your bucket is called mybucket, the URL becomes https://mybucket.mybucket.s3.amazonaws.com/…, causing SSL certificate errors when opened. Manually deleting the redundant subdomain invalidates the signature, so there's no workaround.
Also, HTTPS URL is displayed twice in the menu. The first instance looks good, but the second instance has an additional path component with the bucket name, e.g. https://mybucket.s3.amazonaws.com/mybucket/… thus pointing to an invalid path.