In the following specific case:
- Click 'Ask Question'
- Click the stack snippet button without entering any other text or question titles or anything in the editor first.
When you navigate away from the page (back button, reload, etc.), you currently are not prompted for confirmation with the "unsaved changes" dialog.
This is a request to trigger the unsaved changes confirmation in this case (in addition to the current behavior where it is displayed when you enter text in the editor).
Authoring a code snippet, even if nothing else is entered yet, does represent unsaved work.
Current workaround if you don't want to get bitten by this (for example if your stupid laptop's stupid keyboard has stupid browser back/forward keys right next to the stupid arrows because really? why? how does that make ANY sense??? ... ahem) is to always enter something, even if it's just temporary gibberish, into the editor before clicking the code snippet button.