Continuing #1025 , I seem to have the same issue.

I have SSE-S3 configured Artifacts bucket and for files above 5MB I'm getting the same error as #1025 : failed to put file: x-amz-server-side-encryption header is not supported for this operation.

The call seems to originate here in Argo Workflows (not doing anything funny): https://github.com/argoproj/argo-workflows/blob/2f5e7534c44499a9efce51d12ff87f8c3f725a21/workflow/artifacts/s3/s3.go#L202-L204