Can't use esriControls.ControlsEditingEditorMenu on Child form (C#) ?

[TaiBui]

Hi everyone,

My project include two form: Main form and child form.

Each form contains: 1 MapControl and 1 toolbarcontrol. And I added a ControlsEditingEditorMenu to each toolbarcontrol

I can use ControlsEditingEditorMenu in the main form. But when I open a new form (child form) from the main form, I can't use ControlsEditingEditorMenu (it is disable/ not hightlight when clicking).

I used below codes to add item.

axToolbarControl2.AddItem("esriControls.ControlsEditingEditorMenu", 0, -1, false, 0, esriCommandStyles.esriCommandStyleIconOnly);

Are there anyone know how to fix it ?

Thanks and regards,