In Freshservice, after an incident is resolved, the status of the associated alert/s is also resolved. However, Freshservice keeps a tab on the associated alert/s by default for 30 minutes after this status change. If the alert/s reopen within 30 minutes, the associated incident also reopens.
You can change this behavior if you want, by following these steps:
Head to the Admin pane, scroll down to the ITOM section, and select Alert Rules.
Click on the second tab – Alert Automation Settings – and disable the toggle for 'Reopen Incident'.
That's it! With this feature disabled, an incident won't reopen automatically if an associated alert/s reopens.
Note: The default time period of 30 minutes, that Freshservice tracks the status of a resolved alert for, can be customized. Just head to Admin> Alert Profiles > [profile] > Settings, and update the timeframe as per your preference.