Did you happen to submit this bug to Backblaze for triage? If not, I'll get it to the right people!

> When you're using an SDK, you can set the value of the x-amz-sdk-checksum-algorithm parameter to the algorithm that you want Amazon S3 to use when calculating the checksum. Amazon S3 automatically calculates the checksum value.

> When you're using the REST API, you don't use the x-amz-sdk-checksum-algorithm parameter. Instead, you use one of the algorithm-specific headers (for example, x-amz-checksum-crc32).

https://docs.aws.amazon.com/AmazonS3/latest/userguide/checki...