Hi Khanayat Manoj,
Hope you are doing great.
To answer your question, if there is a change in the host name and IP address, it will reflect in your Site24x7 client for the existing host after the successive data collection and server restart.
About the monitor's data loss, unless the Universal Unique ID (UUID) of the server/device has not changed, the monitor will map itself without any configuration data loss.
To answer your questions better, could you help us with the cloud provider you are using?
Site24x7 IT Infrastructure monitoring team