Thanks for your answers, I actually am trying to build UE5 only and the process build 5197 actions, which seems to be quite the same amount as when I built directly from the Local Windows Debugger (with UE5 as startup project).
I also, for test purpose, switched to Development|PS5 environment, then went back to Development Editor|Win64, aftre that the build process started all over again although I already built it during night.
This is really painful if I have to build all over again when I want to change environment. Am I missing something here again?