Issue with creating event handlers for registered components

I have a package created in RAD Studio C++Builder 10.2 containing a number of new components. I register each component as follows (at the bottom of the .cpp file for a component):

namespace Tmbdstringgrid_component
{
    void __fastcall PACKAGE Register()
    {
         TComponentClass classes[1] = {__classid(TMBDStringGrid)};
         RegisterComponents(L"MyComponents", classes, 0);
    }
}

These components have new event handlers eg:

__property TNotifyEvent OnValueChange = {read=FOnValueChange, write=FOnValueChange};

After the package containing these components is installed, adding one of these components to a Form at design time, and then creating an event handler by double-clicking the event in the Object Inspector, I get the following:

void __fastcall TForm1::MBDNumEdit1ValueChange(TObject *param_0)

Instead of:

void __fastcall TForm1::MBDNumEdit1ValueChange(TObject *Sender)

Can anyone help? Why is it not displaying the correct names as defined in the event type, instead using param_0, param_1, etc?

I suspect it is something to do with how the component is being registered.