diff --git a/custom_components/gree_custom/config_flow.py b/custom_components/gree_custom/config_flow.py
index e42d54d..19d1c66 100755
--- a/custom_components/gree_custom/config_flow.py
+++ b/custom_components/gree_custom/config_flow.py
@@ -1,6 +1,7 @@
 """Config flow to configure the Gree integration."""
 
 from collections.abc import Mapping
+import copy
 from ipaddress import IPv4Address, IPv4Network, ip_address, ip_network
 import logging
 from typing import TYPE_CHECKING, Any, override
@@ -358,11 +359,13 @@ async def async_step_dhcp(
 
                 discover.remove(d)
 
-                # update data
-                new_data = dict(entry_match.data)
-                new_data[CONF_DEVICES][discovery_info.macaddress][
-                    CONF_DEVICE_CONNECTION
-                ][CONF_DEVICE_CONNECTION_LOCAL][CONF_HOST] = discovery_info.ip
+                # update data. Behind a gateway the DHCP MAC is the gateway,
+                # and the configured devices are its sub-units, so use the MAC
+                # of the discovered device. Copy deep, so the entry sees a change.
+                new_data = copy.deepcopy(dict(entry_match.data))
+                new_data[CONF_DEVICES][d.mac][CONF_DEVICE_CONNECTION][
+                    CONF_DEVICE_CONNECTION_LOCAL
+                ][CONF_HOST] = discovery_info.ip
                 # TODO: Check if this only returns True if the IP Changed
                 if (
                     self.hass.config_entries.async_update_entry(
diff --git a/docs/configuration.md b/docs/configuration.md
index 6987f8f..355c6b1 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -116,7 +116,7 @@ Open the device page and choose **Delete** from the three dot menu. The device i
 
 Two mechanisms keep the stored IP address current when a device gets a new one from DHCP:
 
-- Home Assistant reports DHCP leases of Gree devices to the integration. When the MAC matches a configured device, the stored IP is updated and the entry is reloaded. This only updates known devices. It does not start a setup flow for new ones.
+- Home Assistant reports DHCP leases of Gree devices to the integration. When the MAC matches a configured device, or a gateway with configured sub-units (VRF, zone controller), the stored IP of those devices is updated and the entry is reloaded. This only updates known devices. It does not start a setup flow for new ones.
 - When a poll fails, the integration runs a discovery, looks for the device MAC, and retries once with the new IP.
 
 Both need the device to be on a network that Home Assistant can reach with a broadcast. Give the device a fixed IP when it is on another VLAN.