The (Restored in 8.0.6) hover over the Alert List's "Last Updated" column shows the duration of the Alert itself, NOT the total time involved.

Unless you memorize the configuration of this Alert for each of its 3 severity levels, and assume they never change, and never vary by server, nor by database... you must sill open each event to see the "Total blocking duration for all descendants" published under the "Details" tab, then add that to the event duration, for which you must now do time subtraction as there is no "Duration" on the Status line... (another omission).

Having to drill-down is a waste of time when the already available information can be published, within the hover call-out, as:
• Raised at: hh:mm
• Severity duration: hh:mm:ss
• Total Blocking duration: hh:mm:ss

The last duration is what is really important. Alerts do not get raised exactly on the threshold. They can be raised up to 59s after the threshold is met, because sampling is minutely. So, under the current implementation, a blocking threshold of 5 minutes for a red flag can be raised at 5m59s. If the blocking ended at 6m2s, the current bubble show 3 SECONDS duration. IMO this is useless information given the gravity of the underlying event.

If the current "Duration" must persist, please rename it to something meaningful, but, please, make the hover useful by adding the "Total Blocking Duration" as a third line. THAT would make hovering over the Alert page column worth doing - right now it is worthless.

Thanks.