Hello SummerSeaSun,

the process "CCAgent.exe" controls the Simatic Shell.
The WinCC-Stations are sending Multicast-Telegramms
(IP 234.5.6.7) from one to every other to get in contact.

see the FAQ:

"How do you use the SIMATIC shell to configure the terminal bus of a WinCC station?

https://support.industry.siemens.com/cs/ww/en/view/25437381

You should analyse the diagnostic data inside the
folder "C:\Program Files (x86)\Siemens\WinCC\diagnose",
especially the files "WinCC_Sys_0x.log", if you can
find any errors.

Regards

Georg Berghof