We will be upgrading to a new server running Windows Server 2019, will there be any issue installing CS_23 on the new server?
COBOL Server 2.3 is not supported on Windows Server 2019, but it is supported starting with release 4.0.
You may find the product availability page here.
I'd like to point out also that Micro Focus will stop supporting the release 2.3.2 on 22-Sep-2019.
You may find the product support lifecycle page here.