The anomaly disappears from your list of anomalies, and you have the option to undo that action for a few seconds.
A notification badge appears in the bottom-left corner. You can click Undo in the badge before it disappears to restore the anomaly.
To access your anomaly archive click on the arrow next to the number of anomalies at the top of the list and select Archived.
To restore an anomaly in the list, click on the icon that appears in the top-right corner.