diff --git a/bellows/ash.py b/bellows/ash.py
index 48b492ca..c76ab712 100644
--- a/bellows/ash.py
+++ b/bellows/ash.py
@@ -378,7 +378,12 @@ def connection_lost(self, exc: Exception | None) -> None:
         self._ezsp_protocol.connection_lost(exc)
 
     def eof_received(self):
+        _LOGGER.warning("EOF received from remote end")
         self._ezsp_protocol.eof_received()
+        # Return True to prevent the transport from auto-closing.
+        # For serial-over-TCP connections (e.g. ser2net), the remote end may
+        # signal EOF during initialization without intending to close.
+        return True
 
     def _cancel_pending_data_frames(
         self, exc: BaseException = RuntimeError("Connection has been closed")
@@ -445,7 +450,7 @@ def _unstuff_bytes(data: bytes) -> bytes:
         return out
 
     def data_received(self, data: bytes) -> None:
-        _LOGGER.debug("Received data %s", data.hex())
+        _LOGGER.warning("ASH received %d bytes: %s", len(data), data[:32].hex())
         self._buffer.extend(data)
 
         if len(self._buffer) > MAX_BUFFER_SIZE:
@@ -742,5 +747,6 @@ async def send_data(self, data: bytes) -> None:
         )
 
     def send_reset(self) -> None:
+        _LOGGER.warning("Sending ASH reset frame")
         # Some adapters seem to send a NAK immediately but still process the reset frame
         self._write_frame(RstFrame(), prefix=32 * (Reserved.CANCEL,))
diff --git a/bellows/ezsp/__init__.py b/bellows/ezsp/__init__.py
index 7166847e..3b0c339c 100644
--- a/bellows/ezsp/__init__.py
+++ b/bellows/ezsp/__init__.py
@@ -117,6 +117,9 @@ def is_tcp_serial_port(self) -> bool:
 
     async def _startup_reset(self) -> None:
         """Start EZSP and reset the stack."""
+        if self._gw is None:
+            raise EzspError("Gateway is not connected")
+
         # `zigbeed` resets on startup
         if self.is_tcp_serial_port:
             try:
@@ -220,8 +223,21 @@ async def get_xncp_features(self) -> xncp.FirmwareFeatures:
 
     async def disconnect(self):
         self.stop_ezsp()
-        if self._gw:
-            await self._gw.disconnect()
+        if self._gw is not None:
+            try:
+                await self._gw.disconnect()
+            except ConnectionError:
+                # The secondary event loop is dead. Force-close the
+                # underlying TCP socket so ser2net (or similar) releases
+                # the serial port for subsequent connection attempts.
+                try:
+                    ash = self._gw._obj._transport
+                    if ash is not None and ash._transport is not None:
+                        sock = ash._transport.get_extra_info("socket")
+                        if sock is not None:
+                            sock.close()
+                except Exception:
+                    pass
             self._gw = None
 
     async def _command(self, name: str, *args: Any, **kwargs: Any) -> Any:
diff --git a/bellows/thread.py b/bellows/thread.py
index 4311768d..270402f6 100644
--- a/bellows/thread.py
+++ b/bellows/thread.py
@@ -1,6 +1,7 @@
 import asyncio
 from concurrent.futures import ThreadPoolExecutor
 import functools
+import inspect
 import logging
 
 LOGGER = logging.getLogger(__name__)
@@ -14,7 +15,7 @@ def __init__(self):
         self.thread_complete = None
 
     def run_coroutine_threadsafe(self, coroutine):
-        current_loop = asyncio.get_event_loop()
+        current_loop = asyncio.get_running_loop()
         future = asyncio.run_coroutine_threadsafe(coroutine, self.loop)
         return asyncio.wrap_future(future, loop=current_loop)
 
@@ -30,7 +31,7 @@ def _thread_main(self, init_task):
             self.loop = None
 
     async def start(self):
-        current_loop = asyncio.get_event_loop()
+        current_loop = asyncio.get_running_loop()
         if self.loop is not None and not self.loop.is_closed():
             return
 
@@ -95,11 +96,21 @@ def func_wrapper(*args, **kwargs):
             if loop == curr_loop:
                 return call()
             if loop.is_closed():
-                # Disconnected
-                LOGGER.warning("Attempted to use a closed event loop")
-                return
-            if asyncio.iscoroutinefunction(func):
-                future = asyncio.run_coroutine_threadsafe(call(), loop)
+                raise ConnectionError(
+                    "Attempted to use a closed event loop, "
+                    "the connection may have been lost"
+                )
+            if inspect.iscoroutinefunction(func):
+                coro = call()
+                try:
+                    future = asyncio.run_coroutine_threadsafe(coro, loop)
+                except RuntimeError:
+                    # Loop closed between is_closed() check and dispatch
+                    coro.close()
+                    raise ConnectionError(
+                        "Attempted to use a closed event loop, "
+                        "the connection may have been lost"
+                    )
                 return asyncio.wrap_future(future, loop=curr_loop)
             else:
 
diff --git a/bellows/uart.py b/bellows/uart.py
index af274dc8..82043e0b 100644
--- a/bellows/uart.py
+++ b/bellows/uart.py
@@ -33,7 +33,12 @@ def data_received(self, data):
 
     def reset_received(self, code: t.NcpResetCode) -> None:
         """Reset acknowledgement frame receive handler"""
-        LOGGER.debug("Received reset: %r", code)
+        LOGGER.warning(
+            "Received reset: %r (reset_future=%s, startup_reset_future=%s)",
+            code,
+            self._reset_future,
+            self._startup_reset_future,
+        )
 
         if self._reset_future and not self._reset_future.done():
             self._reset_future.set_result(True)
@@ -46,14 +51,15 @@ def reset_received(self, code: t.NcpResetCode) -> None:
     def error_received(self, code: t.NcpResetCode) -> None:
         """Error frame receive handler."""
         if self._reset_future is not None or self._startup_reset_future is not None:
-            LOGGER.debug("Ignoring spurious error during reset: %r", code)
+            LOGGER.warning("Ignoring spurious error during reset: %r", code)
         else:
+            LOGGER.warning("Error received, entering failed state: %r", code)
             self._api.enter_failed_state(code)
 
     async def wait_for_startup_reset(self) -> None:
         """Wait for the first reset frame on startup."""
-        assert self._startup_reset_future is None
-        self._startup_reset_future = asyncio.get_running_loop().create_future()
+        if self._startup_reset_future is None:
+            self._startup_reset_future = asyncio.get_running_loop().create_future()
 
         try:
             await self._startup_reset_future
@@ -68,7 +74,7 @@ def connection_lost(self, exc):
         """Port was closed unexpectedly."""
         super().connection_lost(exc)
 
-        LOGGER.debug("Connection lost: %r", exc)
+        LOGGER.warning("Gateway connection lost: %r", exc)
         reason = exc or ConnectionResetError("Remote server closed connection")
 
         # XXX: The startup reset future must be resolved with an error *before* the
@@ -98,7 +104,7 @@ async def reset(self):
             return await self._reset_future
 
         self._transport.send_reset()
-        self._reset_future = asyncio.get_event_loop().create_future()
+        self._reset_future = asyncio.get_running_loop().create_future()
         self._reset_future.add_done_callback(self._reset_cleanup)
 
         async with asyncio_timeout(RESET_TIMEOUT):
@@ -106,13 +112,18 @@ async def reset(self):
 
 
 async def _connect(config, api):
-    loop = asyncio.get_event_loop()
+    loop = asyncio.get_running_loop()
 
     connection_done_future = loop.create_future()
 
     gateway = Gateway(api, connection_done_future)
     protocol = AshProtocol(gateway)
 
+    # Pre-create the startup reset future before opening the connection so that
+    # reset frames arriving immediately after connect are captured by
+    # reset_received() instead of triggering enter_failed_state().
+    gateway._startup_reset_future = loop.create_future()
+
     if config[zigpy.config.CONF_DEVICE_FLOW_CONTROL] is None:
         xon_xoff, rtscts = True, False
     else:
@@ -135,7 +146,7 @@ async def _connect(config, api):
 
 async def connect(config, api, use_thread=True):
     if use_thread:
-        api = ThreadsafeProxy(api, asyncio.get_event_loop())
+        api = ThreadsafeProxy(api, asyncio.get_running_loop())
         thread = EventLoopThread()
         await thread.start()
         try:
diff --git a/tests/test_ezsp.py b/tests/test_ezsp.py
index d548309a..483ad085 100644
--- a/tests/test_ezsp.py
+++ b/tests/test_ezsp.py
@@ -789,6 +789,30 @@ async def wait_forever(*args, **kwargs):
     assert version_mock.await_count == 1
 
 
+async def test_startup_reset_gw_none():
+    """Test _startup_reset raises EzspError when gateway is None."""
+    ezsp = make_ezsp(
+        config={
+            **DEVICE_CONFIG,
+            zigpy.config.CONF_DEVICE_PATH: "socket://localhost:1234",
+        }
+    )
+    ezsp._gw = None
+
+    with pytest.raises(EzspError, match="Gateway is not connected"):
+        await ezsp._startup_reset()
+
+
+async def test_disconnect_gw_none():
+    """Test disconnect doesn't raise when gateway is already None."""
+    ezsp = make_ezsp()
+    ezsp._gw = None
+
+    await ezsp.disconnect()  # Should not raise
+
+    assert ezsp._gw is None
+
+
 async def test_wait_for_stack_status(ezsp_f):
     assert not ezsp_f._stack_status_listeners[t.sl_Status.NETWORK_DOWN]
 
diff --git a/tests/test_thread.py b/tests/test_thread.py
index 72efa701..e8d35bc2 100644
--- a/tests/test_thread.py
+++ b/tests/test_thread.py
@@ -157,7 +157,8 @@ async def test_proxy_loop_closed():
     obj = mock.MagicMock()
     proxy = ThreadsafeProxy(obj, loop)
     loop.close()
-    proxy.test()
+    with pytest.raises(ConnectionError, match="closed event loop"):
+        proxy.test()
     assert obj.test.call_count == 0