In Freshservice, an incident is automatically resolved if all associated alerts get resolved. If you want to change this behaviour, follow these steps:
Head to Alert Rules in the IT Operations Management section in the Admin page.
You will find yourself on a page listing all the Alert Rules created till date. Select the second tab – Alert automation settings.
In the Alert Automation Settings tab, you will find all the automations related to alerts available. Scroll down to the section – 'Automated changes to incidents based on alerts'.
The automation for resolving an incident if all associated alerts get resolved, is enabled by default. If you do not want the incident to get resolved based on this condition, then simply disable the toggle.
When the toggle is disabled, incidents will remain open even if all associated alerts get resolved.