The IoT WiFi moved from Default (192.168.1.x) to the IoT VLAN (192.168.2.x) with fixed IPs reserved in UniFi. HA 2026.9.3's tplink reconfigure flow ignores the entered host and reconnects to the stored one, so this edits data.host in .storage/core.config_entries with HA stopped, matching entries by MAC and refusing to write unless all 9 match. Backs up core.config_entries first and always restarts hass. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>