I have problem tu use a conte xt menu in the TextBox (or TextEdit) which is placed in the popup content of the popup control. I tried to use a default TextBox's context menu, but right-clicking the TextBox will close the popup. In my app I have customized TextBox's and ScrollBar's context menus to use the selected app theme.
I created a sample which I attached bellow, where you can try to show the popup of the LookUpEdit and there try to invoke the context menu of the search control. Here is the screenshot which looks the final result, but it is imposible to choose any of context menu's items .
This issue happens also when a GridControl is placed into PopupBaseEdit.PopupContentTemplate, so the cell editor is unable to invoke the context menu click, here is the screenshot.
I see that you're using the PopupMenuInfo element. We recommend using it only if you face issues at design time. If I replace it with the PopupMenu element, your context menu works correctly. See the attached screencast. So, please try using the PopupMenu element and provide us with your results.