If I type a comment in VS Code (with the Copilot extension installed) and then press control-return (Ctrl-Enter on other platforms) Copilot correctly opens a new tab with multiple suggestions.
But if I want to keep that around and open a new set of suggestions from another comment, how do I keep from having Copilot remove its own work?
It turns out this has nothing to do with Copilot.
Instead it is related to the way VS Code manages tabs (by default). If the name of the tab is italicized, the tab is treated as ephemeral data, and the next thing you open will replace it. If you want to prevent Copilot from overwriting it, the most direct way to do so is to double-click on the tab, so that the text is no longer italicized. Now VS Code "knows" that you actually care about that text and it should not just delete it willy-nilly.