azure-pipelines-tasks: YAML task for download artifacts does not work with variable

I have been working in Azure Devops Services. I’ve added to my azure devops pipeline step to download artifact from CI pipeline. It is working perfect, but I tried to change artifact name to variables, because this names is using in many places.

strategy:

        runOnce:

          deploy:

            steps:    
      
            - download: $(artifactPipe) 
            
              artifact: $(artifactName)

When I execute this code I receive error:

##[error]Invalid hex string #/11700000/drop (Parameter ‘hex’)

I think this is a bug. I want to ask to fix this ASAP. Because it is block our production pipeline. Thanks in advance.