diff --git a/electrum/gui/qml/qenetwork.py b/electrum/gui/qml/qenetwork.py
index ddc1866db..b25712d13 100644
--- a/electrum/gui/qml/qenetwork.py
+++ b/electrum/gui/qml/qenetwork.py
@@ -207,16 +207,13 @@ class QENetwork(QObject, QtEventListener):
         return self._server
 
     @pyqtSlot(str, bool, bool)
-    def setServerParameters(self, server: str, auto_connect: bool, one_server: bool):
+    def setServerParameters(self, server_str: str, auto_connect: bool, one_server: bool):
         net_params = self.network.get_parameters()
+        server = ServerAddr.from_str_with_inference(server_str)
         if server == net_params.server and auto_connect == net_params.auto_connect and one_server == net_params.oneserver:
             return
-        if server != str(net_params.server):
-            try:
-                server = ServerAddr.from_str_with_inference(server)
-                if not server:
-                    raise Exception('failed to parse')
-            except Exception:
+        if server != net_params.server:
+            if server is None:
                 if not auto_connect:
                     return
                 server = net_params.server
diff --git a/electrum/gui/qt/network_dialog.py b/electrum/gui/qt/network_dialog.py
index d068cec70..eb099cc0f 100644
--- a/electrum/gui/qt/network_dialog.py
+++ b/electrum/gui/qt/network_dialog.py
@@ -462,7 +462,7 @@ class ServerWidget(QWidget, QtEventListener):
         if not self.network._was_started:
             self.update()
             return
-        server = self.server_e.text().strip()
+        server = ServerAddr.from_str_with_inference(self.server_e.text().strip())
         net_params = self.network.get_parameters()
         if server != net_params.server or self.is_auto_connect() != net_params.auto_connect or self.is_one_server() != net_params.oneserver:
             self.set_server()
diff --git a/electrum/interface.py b/electrum/interface.py
index 5e572ab0c..8da607efe 100644
--- a/electrum/interface.py
+++ b/electrum/interface.py
@@ -496,6 +496,7 @@ def _get_cert_path_for_host(*, config: 'SimpleConfig', host: str) -> str:
 class Interface(Logger):
 
     def __init__(self, *, network: 'Network', server: ServerAddr):
+        assert isinstance(server, ServerAddr), f"expected ServerAddr, got {type(server)}"
         self.ready = network.asyncio_loop.create_future()
         self.got_disconnected = asyncio.Event()
         self.server = server
diff --git a/electrum/network.py b/electrum/network.py
index e1b41b8a5..44719ff41 100644
--- a/electrum/network.py
+++ b/electrum/network.py
@@ -886,6 +886,7 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
         queue interface to be started. The actual switch will
         happen when the interface becomes ready.
         """
+        assert isinstance(server, ServerAddr), f"expected ServerAddr, got {type(server)}"
         self.default_server = server
         old_interface = self.interface
         old_server = old_interface.server if old_interface else None
@@ -973,6 +974,7 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
     @ignore_exceptions  # do not kill outer taskgroup
     @log_exceptions
     async def _run_new_interface(self, server: ServerAddr):
+        assert isinstance(server, ServerAddr), f"expected ServerAddr, got {type(server)}"
         if (server in self.interfaces
                 or server in self._connecting_ifaces
                 or server in self._closing_ifaces):
@@ -1508,6 +1510,7 @@ class Network(Logger, NetworkRetryManager[ServerAddr]):
                 # FIXME this should try to honour "healthy spread of connected servers"
                 server = self._get_next_server_to_try()
                 if server:
+                    assert isinstance(server, ServerAddr), f"expected ServerAddr, got {type(server)}"
                     await self.taskgroup.spawn(self._run_new_interface(server))
         async def maintain_healthy_spread_of_connected_servers():
             with self.interfaces_lock: interfaces = list(self.interfaces.values())