When a mongod process is started with 

mongod --enableEncryption --kmipServerName <KMIP Server HostName> \
 --kmipPort <KMIP server port> --kmipServerCAFile ca.pem \
 --kmipClientCertificateFile client.pem

only two KMIP operations listed below are performed by the KMIP Client in MongoDB Enterprise.

1. Create
2. Get

Hence, the Master key remains in the Pre Active state and is not activated.