I have a custom popup with a texteditor component filling it to make it simple to rename something, work very well, sans one little thing. If you right click in the texteditor component itself to access its menu, the menu does come up, but the popup that the texteditor is in disappears. It does work if you select text in the component by left click, dragging, what-not, so I assume that something is closing the popup when the other one pops up, or…?
Does your popup delete itself when another component gets keyboard focus? The menu window will temporarily get focus, so you might have to be a bit smarter about when your popup decides to delete itself.