diff --git a/sleap/gui/utils.py b/sleap/gui/utils.py
index 4f8215706..b974e26e8 100644
--- a/sleap/gui/utils.py
+++ b/sleap/gui/utils.py
@@ -1,6 +1,7 @@
 """Generic module containing utilities used for the GUI."""
 
 import zmq
+import time
 from typing import Optional
 
 
@@ -12,6 +13,7 @@ def is_port_free(port: int, zmq_context: Optional[zmq.Context] = None) -> bool:
     try:
         socket.bind(address)
         socket.unbind(address)
+        time.sleep(0.1)
         return True
     except zmq.error.ZMQError:
         return False
@@ -26,3 +28,28 @@ def select_zmq_port(zmq_context: Optional[zmq.Context] = None) -> int:
     port = socket.bind_to_random_port("tcp://127.0.0.1")
     socket.close()
     return port
+
+
+def find_free_port(port: int, zmq_context: zmq.Context):
+    """Find free port to bind to.
+
+    Args:
+        port: The port to start searching from.
+        zmq_context: The ZMQ context to use.
+
+    Returns:
+        The free port.
+    """
+    attempts = 0
+    max_attempts = 10
+    while not is_port_free(port=port, zmq_context=zmq_context):
+        if attempts >= max_attempts:
+            raise RuntimeError(
+                f"Could not find free port to display training progress after "
+                f"{max_attempts} attempts. Please check your network settings "
+                "or use the CLI `sleap-train` command."
+            )
+        port = select_zmq_port(zmq_context=zmq_context)
+        attempts += 1
+
+    return port
diff --git a/sleap/gui/widgets/monitor.py b/sleap/gui/widgets/monitor.py
index fff8a0327..9a17eecff 100644
--- a/sleap/gui/widgets/monitor.py
+++ b/sleap/gui/widgets/monitor.py
@@ -12,7 +12,7 @@
 import matplotlib.transforms as mtransforms
 from qtpy import QtCore, QtWidgets
 
-from sleap.gui.utils import is_port_free, select_zmq_port
+from sleap.gui.utils import find_free_port
 from sleap.gui.widgets.mpl import MplCanvas
 from sleap.nn.config.training_job import TrainingJobConfig
 
@@ -788,30 +788,6 @@ def _setup_zmq(self, zmq_context: Optional[zmq.Context] = None):
         self.sub = self.ctx.socket(zmq.SUB)
         self.sub.subscribe("")
 
-        def find_free_port(port: int, zmq_context: zmq.Context):
-            """Find free port to bind to.
-
-            Args:
-                port: The port to start searching from.
-                zmq_context: The ZMQ context to use.
-
-            Returns:
-                The free port.
-            """
-            attempts = 0
-            max_attempts = 10
-            while not is_port_free(port=port, zmq_context=zmq_context):
-                if attempts >= max_attempts:
-                    raise RuntimeError(
-                        f"Could not find free port to display training progress after "
-                        f"{max_attempts} attempts. Please check your network settings "
-                        "or use the CLI `sleap-train` command."
-                    )
-                port = select_zmq_port(zmq_context=self.ctx)
-                attempts += 1
-
-            return port
-
         # Find a free port and bind to it.
         self.zmq_ports["publish_port"] = find_free_port(
             port=self.zmq_ports["publish_port"], zmq_context=self.ctx