'puppet ssl clean' does not remove the certificate requests

..Puppet Version: 6.0.4
Puppet Server Version: 6.0.1
OS Name/Version: Centos7

When I get "Error: Could not request certificate: The certificate retrieved from the master does not match the agent's private key...", I use the "puppet ssl clean" as suggested by the error message:

# puppet ssl clean

Notice: Removed private key /etc/puppetlabs/puppet/ssl/private_keys/dbslave.example.com.pem

Notice: Removed public key /etc/puppetlabs/puppet/ssl/public_keys/dbslave.example.com.pem

Notice: Removed certificate /etc/puppetlabs/puppet/ssl/certs/dbslave.example.com.pem

But then I have to clean the certificate request manually, otherwise I get the same error.

# rm /etc/puppetlabs/puppet/ssl/certificate_requests/dbslave.example.com.pem

Desired Behavior:

According to the feature request ( PUP-9156)  it should be cleaned automatically along with the other files.

Puppet configs are all default. I have not overridden any of them.