The help for these options named flags that do not exist, so copying them gives "unknown flag": --sse-customer-key(-base64) is --b2-/--s3-sse-customer-key(-base64), --azurefile-upload-concurrency is --azurefiles-upload-concurrency and --ignore size is --ignore-size. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>