Stack Name validation error detected, while updating provisioned instances using boto3

I have an implementation that uses service catalog, boto3 client to update the provisioned instances. But everytime I do it I keep on getting the following error 1 validation error detected: Value 'stack/SC-603938253459-pp-rqa7btasmj45s/d18d1ce0-8ef2-11ee-9438-02b701d6e6ef' at 'stackName' failed to satisfy constraint: Member must satisfy regular expression pattern: [a-zA-Z][-a-zA-Z0-9]|arn:[-a-zA-Z0-9:/._+]

When you run the regex validation using python or java for the same, the regex matches. I'm not sure if this is a bug in the system or am I missing something in code. The sample code is

client.update_provisioned_product( ProvisionedProductId=product['Id'], ProductId=product['ProductId'], ProvisioningArtifactName=product['ProvisioningArtifactName'] )