us-east-1.index.mjs.BROWSABLE_PREFIX_CONFIGS has the right bucket names.lambda.amazonaws.com.edgelambda.amazonaws.com.s3:ListBucket for the intended prefixes.$LATEST.Origin request.Viewer response./beta/ works./beta redirects to /beta/.The current standard browse roots include 8k.art/beta/, 8k.press/beta/, and define.com/beta/. Each should map to its own matching S3 bucket prefix and, when enabled, its own .directory-index.json.
Every browsable prefix must route through a CloudFront behavior with the current numbered Lambda@Edge version attached at Origin response. Lambda@Edge does not run $LATEST.