What it sounds like you’re describing should have worked, but I’m not certain I’m clear on exactly what you’re doing.
If you are leaving the files in the same directory and only renaming them, you should be able to do that in Visual Studio (right-click on the file and “Rename”).
If you are moving the files to a new location, even if you are keeping the same filename, you need to remove the file from your project (right-click, “Remove”), then move the file to the new directory, then add the existing file to your project (right-click on the target filter within the Visual Studio hierarchy, select “Add Existing Item”, and browse to your file(s) ).
At that point, I would close Visual Studio, delete the Intermediate, .vs and Binaries folders, Generate Project Files, open Visual Studio, allow Visual Studio to completely scan for all includes etc., then try your build. It should work.
You’re right, having to create a new file and copy code over just to rename a file without changing the directory is not okay.
If you have a problem like this in the future where you need to revert to a backup; rather than lose your work, you can move or copy your new code files to a directory outside your project. Then, after you revert to your backup project, just move the saved files into the proper directories within your project with the filenames you want. At that point use “Add Existing Item” from within Visual Studio and go from there. It’s still a bit of a pain as a workaround, but less troubling than what you’re describing.