Horde doesn't build Editor PCBs properly when not modifying project C++ (e.g. only modifying plugin C++)

The current situation is as such:

I have warnings in my project’s C++. When I modify project C++ and run incremental builds in Horde (that also generate Editor PCBs for Unreal Game Sync to retrieve them), Horde will rightfully report the build succeeded with Warnings. In this case, UGS also retrieves the editor PCBs successfully and non-engineers can launch the editor.

However, let’s say I only modify plugin C++ and then run the incremental build. Based on the logs, the project’s editor dlls aren’t recompiled again. And then Horde reports the build as succeeding without warnings (which isn’t right), and then UGS doesn’t sync PCBs properly and non-engineers are not even able to launch the editor.

I’m using all the default examples provided by Epic with very minimal changes (e.g. using BuildEditorAndTools.xml BuildGraph).

What is wrong with my setup that’s causing these problems?

So far, my workaround to this problem is to make a minor comment change in a project’s C++ file and then run the incremental build again. This forces the editor PCBs to be generated properly and we can continue work.