Action is not shown on screen

I have an action that I’m using it on multiple screens. This action appears on all screens and works as expected. The only exception I am facing are “POOrderEntry” and “SubcontractEntry” screens that doesn’t show the Action on screen. Here is the Action:

public PXAction<POOrder> customRoute;
[PXButton(CommitChanges = true, Category = Messages.ApprovalCategory, DisplayOnMainToolbar = true, IsLockedOnToolbar = true)]
[PXUIField(DisplayName = EPMessages.CustomRoute, MapEnableRights = PXCacheRights.Select, MapViewRights = PXCacheRights.Select)]

protected virtual IEnumerable CustomRoute(PXAdapter adapter)
{
    Base.Save.Press();

    // Do stuff here

    return adapter.Get();
}

Can anyone help why this works on all screens but these two?