diff --git a/unit-tests/dds/device-2nd-client.py b/unit-tests/dds/device-2nd-client.py
index e93247e7a4..c77ce85afd 100644
--- a/unit-tests/dds/device-2nd-client.py
+++ b/unit-tests/dds/device-2nd-client.py
@@ -8,7 +8,15 @@
 
 
 participant = dds.participant()
-participant.init( 123, f'client-{log.nested.strip()}' )
+# in some cases we need a bigger buffer for our messages, to avoid missing messages sent
+settings = { "device" :
+                 { "notification" :
+                       { "history" :
+                             { "depth" : 60 }
+                         }
+                   }
+             }
+participant.init( 123, f'client-{log.nested.strip()}', settings )
 
 
 info = dds.message.device_info()
diff --git a/unit-tests/dds/device-broadcaster.py b/unit-tests/dds/device-broadcaster.py
index 0229be6c7b..8a56ea50e0 100644
--- a/unit-tests/dds/device-broadcaster.py
+++ b/unit-tests/dds/device-broadcaster.py
@@ -40,7 +40,9 @@ def close_server( instance ):
     Close the instance returned by broadcast_device()
     """
     global servers
-    del servers[instance]  # throws if does not exist
+    server = servers[instance]["server"]  # throws if does not exist
+    server.broadcast_disconnect()
+    del servers[instance]
 
 
 # From here down, we're in "interactive" mode (see test-device-init.py)
diff --git a/unit-tests/dds/device-init-server.py b/unit-tests/dds/device-init-server.py
index a36f9abf71..ee58c00e40 100644
--- a/unit-tests/dds/device-init-server.py
+++ b/unit-tests/dds/device-init-server.py
@@ -11,7 +11,15 @@
 
 
 participant = dds.participant()
-participant.init( 123, "device-init-server" )
+# in some cases we need a bigger buffer for our messages, to avoid missing messages sent
+settings = { "device" :
+                 { "notification" :
+                       { "history" :
+                             { "depth" : 60 }
+                         }
+                   }
+             }
+participant.init( 123, "device-init-server", settings )
 
 
 def test_one_stream():
@@ -77,8 +85,15 @@ def notification_flooder():
         i = 0
         while server is not None:
             i += 1
-            log.d( f'----> {i}' )
-            server.publish_notification( { 'id' : 'some-notification', 'counter' : i } )
+            #log.d( f'----> {i}' )
+            try:
+                server.publish_notification( { 'id' : 'some-notification', 'counter' : i } )
+            except AttributeError as e:
+                # another thread had just made the server None at this point
+                if not server:
+                    log.d("tried calling publish_notification but server is None, was close_server called?")
+                else:
+                    raise e # unexpected error
             sleep( 0.005 )
     global notification_thread
     notification_thread = threading.Thread( target=notification_flooder )