Unable to Add Custom Action to GI Mass Actions Menu

Hello everyone,

I’m trying to add a custom action to the Generic Inquiry (GI) Mass Actions menu, but I haven’t been able to make it work.

The custom action is defined in a graph extension as follows:

namespace PX.Objects.PM {
  public class ProjectEntry_Extension: PXGraphExtension < ProjectEntry > {
    public override void Initialize() {
      base.Initialize();
      cusMassAction.IsMass = true;
    }
    #region Actions
    // Mass Action
    public PXAction < PMProject > cusMassAction;
    [PXProcessButton(CommitChanges = true, Category = "Processing")]
    [PXMassAction]
    [PXUIField(DisplayName = "Cus Mass Action", IsDirty = true)]
    protected IEnumerable CusMassAction(PXAdapter adapter) {
      bool isMassProcess = adapter.MassProcess;
      foreach(PMProject project in adapter.Get < PMProject > ()) {
        project.Status = "S";
        Base.Project.Cache.Update(project);
      }

      Base.Actions.PressSave();
      return adapter.Get();
    }
    #endregion
  }
}

The action works correctly from the Actions menu, but it doesn’t appear in the GI’s Mass Actions dropdown

even though I have enabled the “Enable Mass Actions on Records” option.

Do I need to add something specific (like attributes, parameters, or graph connections) for it to appear in the GI Mass Actions list?

Any examples or suggestions would be greatly appreciated.
Thanks