Refreshing whole sheet

If you want to discard changes on your sheet or update issues that are present on it you can use Refresh Sheet button (1).

After pressing it you will be presented with "Refresh Issue" prompt that makes sure, you clicked on Refresh Sheet button intentionally, and inform you about possible lose of changes (3).

Confirming refresh will remove any changes you made to issues, query Jira for updates made to them and insert them into your worksheet and remove all new issues you were about to create.