diff --git a/tests/tui_gateway/test_goal_command.py b/tests/tui_gateway/test_goal_command.py
index f67e54a5376..ad2cb9f3449 100644
--- a/tests/tui_gateway/test_goal_command.py
+++ b/tests/tui_gateway/test_goal_command.py
@@ -34,7 +34,7 @@ def hermes_home(tmp_path, monkeypatch):
 
 
 @pytest.fixture()
-def server(hermes_home):
+def server(hermes_home, monkeypatch):
     # Mocks are scoped to the initial import only (see
     # tests/tui_gateway/test_protocol.py for the rationale).
     with patch.dict(
@@ -46,6 +46,21 @@ def server(hermes_home):
     ):
         mod = importlib.import_module("tui_gateway.server")
 
+    # Pin config resolution to the isolated HERMES_HOME. Sibling test
+    # files (test_billing_rpc, test_delegation_session_lifecycle,
+    # test_gateway_owned_session_reap, ...) import tui_gateway.server at
+    # collection time — BEFORE the conftest env isolation runs — so the
+    # module-level ``_hermes_home = get_hermes_home()`` snapshot freezes
+    # the developer's real home. When any of them precede this file in
+    # the same process, ``importlib.import_module`` returns that cached
+    # module and ``_load_cfg()`` would read the REAL config.yaml (e.g. a
+    # local MoA preset) instead of the one ``_write_moa_config`` writes.
+    # Also reset the mtime-keyed config cache; monkeypatch restores the
+    # originals on teardown so nothing leaks to later tests either.
+    monkeypatch.setattr(mod, "_hermes_home", hermes_home)
+    monkeypatch.setattr(mod, "_cfg_cache", None)
+    monkeypatch.setattr(mod, "_cfg_mtime", None)
+    monkeypatch.setattr(mod, "_cfg_path", None)
     yield mod
     # Reset module-level session state without re-importing. importlib.reload
     # would re-register the module's atexit hooks (ThreadPoolExecutor