Why engine does not recognize C++ changes in the Patch?

I have successfully created a patch to my game with some multiple changes in blueprints and also some modifications in C++ after the released version. The problem is, after I installed the patch in to my game all the blueprint changes are seems to be updated but not C++ changes (It remains the same as the release version). It seems like C++ changes are not included in the patch. I don’t why it is happing and I just followed the extract steps from Unreal Documentation (https://docs.unrealengine.com/en-US/SharingAndReleasing/Patching/GeneralPatching/HowToCreatePatch/index.html)

What is the reason for this? and please let me know in the answers if there is any solution for this. Cheers!

For those who come here in future try this : C++ files are included in .dll and .exe files, SO just replacing the .pak file is not enough. You have to replace previously mentioned files as well.