It is not recommended to have "." in device naming convention. "Truncate Device Name" is checked by default in NCM; which would consider
. (dot) as truncating factor for device name.
As a workaround in NCM, below steps can be implemented.
1) Navigate to Tools -> System Administration.
2) The below page would open. Expand Global -> Device Options, Click on "Device Naming Scheme", look for option "Truncate Device Name".
3) Uncheck the checkbox and click "Apply". Do Refresh on UI.