diff --git a/custom_components/nvidia_shield/config_flow.py b/custom_components/nvidia_shield/config_flow.py
index 963513b..f2851a7 100644
--- a/custom_components/nvidia_shield/config_flow.py
+++ b/custom_components/nvidia_shield/config_flow.py
@@ -280,21 +280,25 @@ class NvidiaShieldConfigFlow(config_entries.ConfigFlow, domain=DOMAIN):
             for entry in self._async_current_entries():
                 if getattr(entry, "unique_id", None) != mac:
                     continue
-                # Known device — update hosts only on a real IP change
-                # (core androidtv_remote pattern, simplified): an explicitly
-                # configured host that moved to the discovery address.
+                # Known device — per-host updates (t21 F2): each host is
+                # tracked independently against the discovery address.
+                # - a blank (auto-detect) host self-heals from the address;
+                # - a stale protocol host is the IP change and is updated;
+                # - a deliberately-different ADB host (an explicit override
+                #   that differs from both the address and the stored
+                #   protocol host) is never clobbered.
                 protocol_host = entry.options.get(CONF_PROTOCOL_HOST, "")
                 adb_host = entry.options.get(CONF_ADB_HOST, "")
-                if (protocol_host and protocol_host != host) or (
-                    adb_host and adb_host != host
-                ):
+                options = dict(entry.options)
+                if protocol_host != host:
+                    options[CONF_PROTOCOL_HOST] = host
+                if not adb_host or adb_host == protocol_host:
+                    # blank (self-heal) or auto-synced alongside the protocol
+                    # host — safe to follow the device address on discovery
+                    options[CONF_ADB_HOST] = host
+                if options != entry.options:
                     self.hass.config_entries.async_update_entry(
-                        entry,
-                        options={
-                            **entry.options,
-                            CONF_PROTOCOL_HOST: host,
-                            CONF_ADB_HOST: host,
-                        },
+                        entry, options=options
                     )
                     self.hass.config_entries.async_schedule_reload(entry.entry_id)
                 return self.async_abort(reason="already_configured")
diff --git a/tests/test_standalone_setup.py b/tests/test_standalone_setup.py
index 778ce9c..fba19e5 100644
--- a/tests/test_standalone_setup.py
+++ b/tests/test_standalone_setup.py
@@ -436,6 +436,34 @@ class TestZeroconfDiscovery:
         hass = FakeHass(str(tmp_path))
         flow.hass = hass
 
+        # both hosts already hold the discovered address: nothing changes
+        entry = SimpleNamespace(
+            unique_id="aa:bb:cc:dd:ee:ff",
+            options={
+                CONF_PROTOCOL_ENABLED: True,
+                CONF_PROTOCOL_HOST: "192.168.1.50",
+                "adb_host": "192.168.1.50",
+            },
+            entry_id="e1",
+            title="Shield",
+        )
+        sys.modules[__name__]._zc_holder.entries[:] = [entry]
+
+        result = await flow.async_step_zeroconf(
+            self._discovery(props={"mac": "aa:bb:cc:dd:ee:ff"})
+        )
+
+        assert result == {"type": "abort", "reason": "already_configured"}
+        assert hass.config_entries.updating_entry_calls == []  # no IP change
+        assert hass.config_entries.reloaded_entry_ids == []
+
+    async def test_blank_adb_host_self_heals_from_the_discovery_address(self, tmp_path):
+        """F2: a blank (auto-detect) adb host follows a same-IP rediscovery."""
+        module = _form_module()
+        flow = module.NvidiaShieldConfigFlow()
+        hass = FakeHass(str(tmp_path))
+        flow.hass = hass
+
         entry = SimpleNamespace(
             unique_id="aa:bb:cc:dd:ee:ff",
             options={CONF_PROTOCOL_ENABLED: True, CONF_PROTOCOL_HOST: "192.168.1.50"},
@@ -449,8 +477,40 @@ class TestZeroconfDiscovery:
         )
 
         assert result == {"type": "abort", "reason": "already_configured"}
-        assert hass.config_entries.updating_entry_calls == []  # no IP change
-        assert hass.config_entries.reloaded_entry_ids == []
+        # only the adb host was filled (self-heal), protocol already current:
+        update = hass.config_entries.updating_entry_calls[0][1]["options"]
+        assert update["adb_host"] == "192.168.1.50"
+        assert update["protocol_host"] == "192.168.1.50"
+        assert hass.config_entries.reloaded_entry_ids == ["e1"]
+
+    async def test_deliberately_different_adb_host_is_never_clobbered(self, tmp_path):
+        """F2: an explicit ADB override survives a protocol-host IP change."""
+        module = _form_module()
+        flow = module.NvidiaShieldConfigFlow()
+        hass = FakeHass(str(tmp_path))
+        flow.hass = hass
+
+        entry = SimpleNamespace(
+            unique_id="aa:bb:cc:dd:ee:ff",
+            options={
+                CONF_PROTOCOL_ENABLED: True,
+                CONF_PROTOCOL_HOST: "10.0.0.1",  # stale (IP moved)
+                "adb_host": "10.0.0.9",  # deliberate ADB override
+            },
+            entry_id="e1",
+            title="Shield",
+        )
+        sys.modules[__name__]._zc_holder.entries[:] = [entry]
+
+        result = await flow.async_step_zeroconf(
+            self._discovery(props={"mac": "aa:bb:cc:dd:ee:ff"})
+        )
+
+        assert result == {"type": "abort", "reason": "already_configured"}
+        update = hass.config_entries.updating_entry_calls[0][1]["options"]
+        assert update["protocol_host"] == "192.168.1.50"  # protocol followed
+        assert update["adb_host"] == "10.0.0.9"  # override untouched
+        assert hass.config_entries.reloaded_entry_ids == ["e1"]
 
 
 class TestAppsMapOptionsEditor: