When making a pull request code comment and two days later the "resolve" button is clicked for that comment, then the rendered text in the code comment sidebar says "X resolved 2 days ago" instead of "X resolved moments ago" (or similar).

When opening the "Code comments" tab of the pull requests to see all code comments, the "last update" column does seem to render it correctly. So it seems like the code comment side bar renders the "resolve" comment using the timestamp of the resolved comment instead of its own timestamp.