diff --git a/electrum/interface.py b/electrum/interface.py
index 4b5d0c818..cf6d52821 100644
--- a/electrum/interface.py
+++ b/electrum/interface.py
@@ -140,6 +140,7 @@ class NotificationSession(RPCSession):
         self.cache = {}
         self._msg_counter = itertools.count(start=1)
         self.interface = interface
+        self.taskgroup = interface.taskgroup
         self.cost_hard_limit = 0  # disable aiorpcx resource limits
 
     async def handle_request(self, request):
@@ -267,11 +268,6 @@ class ConnectError(NetworkException): pass
 
 
 class _RSClient(RSClient):
-    def __init__(self, *, transport=None, **kwargs):
-        if transport is None:
-            transport = PaddedRSTransport
-        RSClient.__init__(self, transport=transport, **kwargs)
-
     async def create_connection(self):
         try:
             return await super().create_connection()
@@ -310,7 +306,8 @@ class PaddedRSTransport(RSTransport):
         self._sbuffer_has_data_evt.set()
         self._maybe_consume_sbuffer()
 
-    def _maybe_consume_sbuffer(self):
+    def _maybe_consume_sbuffer(self) -> None:
+        """Maybe take some data from sbuffer and send it on the wire."""
         if not self._can_send.is_set() or self.is_closing():
             return
         buf = self._sbuffer
@@ -376,7 +373,7 @@ class PaddedRSTransport(RSTransport):
     def connection_made(self, transport: asyncio.BaseTransport):
         super().connection_made(transport)
         if isinstance(self.session, NotificationSession):
-            coro = self.session.interface.taskgroup.spawn(self._poll_sbuffer())
+            coro = self.session.taskgroup.spawn(self._poll_sbuffer())
             self._sbuffer_task = self.loop.create_task(coro)
         else:
             # This a short-lived "fetch_certificate"-type session.
@@ -716,9 +713,13 @@ class Interface(Logger):
         sslc = ssl.SSLContext(protocol=ssl.PROTOCOL_TLS_CLIENT)
         sslc.check_hostname = False
         sslc.verify_mode = ssl.CERT_NONE
-        async with _RSClient(session_factory=RPCSession,
-                             host=self.host, port=self.port,
-                             ssl=sslc, proxy=self.proxy) as session:
+        async with _RSClient(
+            session_factory=RPCSession,
+            host=self.host, port=self.port,
+            ssl=sslc,
+            proxy=self.proxy,
+            transport=PaddedRSTransport,
+        ) as session:
             asyncio_transport = session.transport._asyncio_transport  # type: asyncio.BaseTransport
             ssl_object = asyncio_transport.get_extra_info("ssl_object")  # type: ssl.SSLObject
             return ssl_object.getpeercert(binary_form=True)
@@ -787,9 +788,13 @@ class Interface(Logger):
 
     async def open_session(self, sslc, exit_early=False):
         session_factory = lambda *args, iface=self, **kwargs: NotificationSession(*args, **kwargs, interface=iface)
-        async with _RSClient(session_factory=session_factory,
-                             host=self.host, port=self.port,
-                             ssl=sslc, proxy=self.proxy) as session:
+        async with _RSClient(
+            session_factory=session_factory,
+            host=self.host, port=self.port,
+            ssl=sslc,
+            proxy=self.proxy,
+            transport=PaddedRSTransport,
+        ) as session:
             self.session = session  # type: NotificationSession
             self.session.set_default_timeout(self.network.get_network_timeout_seconds(NetworkTimeout.Generic))
             try: