I created a private repository for two library packages and added both with the PCM (Plugin and Content Manager). The libraries are intended for adding them to the project library list, if they are needed, not for the global library list. But everytime I start KiCad, it adds all libraries to the global list. After this, I delete them and after the next start if KiCad they are still there.
Is there any way to prevent kicad from adding the libraries?
You can disable this in preferences.
If you don’t want to disable this behavior globally then you can just disable the libs in global lib table, PCM will not readd them because they are already in the lib table, but you won’t see them in symbol/library choosers if they are disabled.