diff --git a/api/profiles.py b/api/profiles.py
index 27057792..c1d4aaa9 100644
--- a/api/profiles.py
+++ b/api/profiles.py
@@ -40,6 +40,7 @@ _CLONE_CONFIG_FILES = ['config.yaml', '.env', 'SOUL.md']
 # base home, which would disable isolation detection. Snapshot it here at import
 # time (before init_profile_state runs) and use the snapshot in the detector.
 _INITIAL_HERMES_HOME = os.getenv('HERMES_HOME', '').strip()
+_ISOLATED_SYMLINK_WARNING_EMITTED = False
 
 # ── Module state ────────────────────────────────────────────────────────────
 _active_profile = 'default'
@@ -152,6 +153,15 @@ def _is_isolated_profile_mode() -> bool:
     # i.e., parent dir is named 'profiles' and grandparent exists
     if p.parent.name == 'profiles' and p.parent.parent.exists():
         return True
+    if p.is_symlink():
+        global _ISOLATED_SYMLINK_WARNING_EMITTED
+        if not _ISOLATED_SYMLINK_WARNING_EMITTED:
+            logger.warning(
+                "HERMES_HOME symlink %s does not literally match */profiles/<name>; "
+                "isolated profile mode is disabled unless the literal profile path is used.",
+                p,
+            )
+            _ISOLATED_SYMLINK_WARNING_EMITTED = True
     return False
 
 
@@ -325,9 +335,12 @@ def get_active_profile_name() -> str:
     """Return the currently active profile name.
 
     Priority:
-      1. Thread-local (set per-request from hermes_profile cookie) — issue #798
-      2. Process-level default (_active_profile)
+      1. Isolated-profile deployment name from the configured HERMES_HOME path
+      2. Thread-local (set per-request from hermes_profile cookie) — issue #798
+      3. Process-level default (_active_profile)
     """
+    if _is_isolated_profile_mode():
+        return _isolated_profile_name()
     tls_name = getattr(_tls, 'profile', None)
     if tls_name is not None:
         return tls_name
@@ -1009,8 +1022,12 @@ def init_profile_state() -> None:
     module-level cached paths.  Called once from config.py after imports.
     """
     global _active_profile
-    _active_profile = _read_active_profile_file()
-    home = get_active_hermes_home()
+    if _is_isolated_profile_mode():
+        _active_profile = _isolated_profile_name()
+        home = Path(_INITIAL_HERMES_HOME).expanduser()
+    else:
+        _active_profile = _read_active_profile_file()
+        home = get_active_hermes_home()
     _set_hermes_home(home)
     install_cron_scheduler_profile_isolation()
     _reload_dotenv(home)
diff --git a/tests/test_issue2698_isolated_hermes_home.py b/tests/test_issue2698_isolated_hermes_home.py
index d685342c..232094f1 100644
--- a/tests/test_issue2698_isolated_hermes_home.py
+++ b/tests/test_issue2698_isolated_hermes_home.py
@@ -16,9 +16,14 @@ import pytest
 import api.profiles as _profiles_mod
 from api.profiles import (
     _is_isolated_profile_mode,
+    clear_request_profile,
     list_profiles_api,
     create_profile_api,
     delete_profile_api,
+    get_active_hermes_home,
+    get_active_profile_name,
+    init_profile_state,
+    set_request_profile,
     switch_profile,
 )
 
@@ -187,6 +192,71 @@ class TestListProfilesInIsolatedMode:
                                 assert len(profiles) == 1
 
 
+class TestIsolatedRuntimePinning:
+    """Test that isolated mode pins both detection and active runtime home."""
+
+    def test_get_active_profile_name_ignores_tls_and_global_in_isolated_mode(self, temp_single_profile):
+        """Isolated mode must ignore request TLS and process-global active profile."""
+        base_home = temp_single_profile.parent.parent
+        env_dict = {
+            "HERMES_HOME": str(temp_single_profile),
+            "HERMES_BASE_HOME": "",
+        }
+        with mock.patch.dict(os.environ, env_dict, clear=False):
+            with mock.patch("api.profiles._DEFAULT_HERMES_HOME", base_home):
+                with mock.patch("api.profiles._INITIAL_HERMES_HOME", str(temp_single_profile)):
+                    with mock.patch("api.profiles._active_profile", "other_profile"):
+                        set_request_profile("tls_profile")
+                        try:
+                            assert get_active_profile_name() == "user1"
+                        finally:
+                            clear_request_profile()
+
+    @pytest.mark.parametrize("active_profile_contents", [None, "user2"])
+    def test_init_profile_state_pins_runtime_home_to_isolated_profile(
+        self,
+        temp_single_profile,
+        monkeypatch,
+        active_profile_contents,
+    ):
+        """init_profile_state must ignore the base active_profile file in isolated mode."""
+        base_home = temp_single_profile.parent.parent
+        other_profile = base_home / "profiles" / "user2"
+        other_profile.mkdir()
+        for subdir in ["memories", "sessions", "skills", "skins", "logs", "plans", "workspace", "cron"]:
+            (other_profile / subdir).mkdir(exist_ok=True)
+
+        active_profile_file = base_home / "active_profile"
+        if active_profile_contents is None:
+            active_profile_file.unlink(missing_ok=True)
+        else:
+            active_profile_file.write_text(active_profile_contents, encoding="utf-8")
+
+        monkeypatch.setenv("HERMES_HOME", str(temp_single_profile))
+        monkeypatch.setenv("HERMES_BASE_HOME", "")
+        monkeypatch.setattr(_profiles_mod, "_DEFAULT_HERMES_HOME", base_home)
+        monkeypatch.setattr(_profiles_mod, "_INITIAL_HERMES_HOME", str(temp_single_profile))
+        monkeypatch.setattr(_profiles_mod, "_active_profile", "default")
+        monkeypatch.setattr(_profiles_mod, "install_cron_scheduler_profile_isolation", lambda: None)
+
+        reloaded = []
+        real_reload_dotenv = _profiles_mod._reload_dotenv
+
+        def _record_reload(home):
+            reloaded.append(home)
+            return real_reload_dotenv(home)
+
+        monkeypatch.setattr(_profiles_mod, "_reload_dotenv", _record_reload)
+
+        init_profile_state()
+
+        assert _profiles_mod._active_profile == "user1"
+        assert get_active_profile_name() == "user1"
+        assert get_active_hermes_home() == temp_single_profile
+        assert Path(os.environ["HERMES_HOME"]) == temp_single_profile
+        assert reloaded == [temp_single_profile]
+
+
 class TestProfileMutationsInIsolatedMode:
     """Test that create/delete/switch are rejected (403) in isolated mode."""