WinCC Appl." and "WinCC Appl.(stby) Issue

Hello Everyone,

After replacing burnt CP1623s with new ones, configuring new MAC addresses, and creating a new WinCC project, we're unable to establish a connection to the PLC. The old project, however, functions correctly. We've identified a potential issue with the connection tags in the new project being incorrectly linked to "WinCC Appl." instead of "WinCC Appl.(stby)". and i have also observed that both options are displaying WinCC Appl." and "WinCC Appl.(stby)"in named connection tags.

A screenshot of the tag management showing the incorrect connection has been attached for reference.

Why are the connection tags in the new project incorrectly linked, and how can we correct this to establish a connection with WinCC Appl.(stby)

We have 2 server ,6 OS and 7 AS in my project

WinCC v7.4

Step 7 v5.6

and all AS 410-5H

Now my both servers are running but When I stop the SERVER 1, all OS are disconnected. It means OS are not connected with Server 2. When I check the server data at OS, its just showing server, server 2 is not showing in OS server data

What Can be the reason?

where am i made mistake?