Modify the following launch agents to stop FortiClient from starting at boot:
File: /Library/LaunchAgents/com.fortinet.forticlient.credential_store.plist
<key>RunAtLoad</key>
<false/>
<key>KeepAlive</key>
<false/>
After rebooting, check running processes to confirm FortiClient no longer starts automatically.
ps aux | grep -i forti
If FortiClient does not appear in the output, the changes were successful. For more details, refer to the official docs.