diff --git a/EvoScientist/channels/channel_manager.py b/EvoScientist/channels/channel_manager.py
index b8c0f3b..f69c36b 100644
--- a/EvoScientist/channels/channel_manager.py
+++ b/EvoScientist/channels/channel_manager.py
@@ -757,7 +757,16 @@ class ChannelManager:
         """Start the HTTP health-check endpoint (if configured)."""
         if self._health_port and self._health_server is None:
             self._health_server = _HealthServer(self, self._health_port)
-            await self._health_server.start()
+            try:
+                await self._health_server.start()
+            except OSError as e:
+                logger.warning(
+                    "Health server failed to bind on port %s: %s — "
+                    "health endpoint disabled, channel will still start normally.",
+                    self._health_port,
+                    e,
+                )
+                self._health_server = None
 
     async def stop_health(self) -> None:
         """Stop the HTTP health-check endpoint."""
diff --git a/EvoScientist/cli/channel.py b/EvoScientist/cli/channel.py
index 82dcb7f..e2c20de 100644
--- a/EvoScientist/cli/channel.py
+++ b/EvoScientist/cli/channel.py
@@ -445,8 +445,11 @@ def _start_channels_bus_mode(
         try:
             loop.run_until_complete(_run())
         except Exception as e:
-            _channel_logger.error(f"Bus thread error: {e}")
+            _channel_logger.error(
+                "Bus thread terminated with error: %s", e, exc_info=True
+            )
         finally:
+            _channel_logger.debug("Bus thread event loop closed")
             loop.close()
 
     thread = threading.Thread(target=_bus_thread_entry, daemon=True)
diff --git a/EvoScientist/cli/commands.py b/EvoScientist/cli/commands.py
index b870bad..f8574ef 100644
--- a/EvoScientist/cli/commands.py
+++ b/EvoScientist/cli/commands.py
@@ -504,10 +504,6 @@ def serve(
     Starts all configured channels and processes messages via the agent.
     Press Ctrl+C to shut down.
     """
-    import nest_asyncio  # type: ignore[import-untyped]
-
-    nest_asyncio.apply()
-
     from ..config import apply_config_to_env, get_effective_config
 
     cli_overrides = {}
diff --git a/EvoScientist/stream/display.py b/EvoScientist/stream/display.py
index 898e2ea..2ce3483 100644
--- a/EvoScientist/stream/display.py
+++ b/EvoScientist/stream/display.py
@@ -1068,10 +1068,6 @@ def _run_streaming(
     Returns:
         The final response text.
     """
-    import nest_asyncio
-
-    nest_asyncio.apply()
-
     state = _state if _state is not None else StreamState()
     _thinking_sent = False
     _todo_sent = False
@@ -1180,11 +1176,32 @@ def _run_streaming(
         vertical_overflow="visible",
     ) as live:
         live.update(create_streaming_display(is_waiting=True))
+        # Determine how to run the async streaming coroutine.
+        # - In TUI mode (Textual), there's already a running event loop;
+        #   nest_asyncio is needed to allow run_until_complete inside it.
+        # - In serve/CLI mode, the main thread has no running loop;
+        #   use a fresh event loop directly (no nest_asyncio needed or wanted,
+        #   since nest_asyncio.apply() patches globally and breaks the bus
+        #   thread's event loop Task-context detection).
         try:
-            loop = _get_event_loop()
+            running_loop = asyncio.get_running_loop()
         except RuntimeError:
-            # No current event loop
-            loop = _create_event_loop()
+            running_loop = None
+
+        if running_loop is not None:
+            # Already inside a running loop (TUI) — must use nest_asyncio.
+            # NOTE: nest_asyncio.apply() is global and irreversible within
+            # the process; avoid mixing TUI and serve modes in one process.
+            import nest_asyncio  # type: ignore[import-untyped]
+
+            nest_asyncio.apply()
+            loop = running_loop
+        else:
+            # No running loop (serve/CLI) — create a fresh one
+            try:
+                loop = _get_event_loop()
+            except RuntimeError:
+                loop = _create_event_loop()
 
         async def _run_with_refresh() -> None:
             async def _periodic_refresh() -> None: