diff --git a/MultiTerm.Core/ViewModel/CommunicationDataViewModel.cs b/MultiTerm.Core/ViewModel/CommunicationDataViewModel.cs
index 0330a9f..2289604 100644
--- a/MultiTerm.Core/ViewModel/CommunicationDataViewModel.cs
+++ b/MultiTerm.Core/ViewModel/CommunicationDataViewModel.cs
@@ -98,7 +98,11 @@ public partial class CommunicationDataViewModel : ObservableObject
 
             // set new newline separator type and overwrite data collection (triggers property changed)
             this.currentReceiveNewlineSeparatorType = (NewlineSeparatorType)receiveNewlineSeparatorType;
+            // update collection, invoke ui thread if necessary
+            ContextHelpers.InvokeIfNecessary(this.uiContext, (Action)delegate
+            {
             this.ReceivedData = ReorderDataCollection(this.ReceivedData, this.currentReceiveNewlineSeparatorType); 
+            });
         }
         if (sendNewlineSeparatorType != null)
         {
@@ -107,7 +111,11 @@ public partial class CommunicationDataViewModel : ObservableObject
 
             // set new newline separator type and overwrite data collection (triggers property changed)
             this.currentSentNewlineSeparatorType = (NewlineSeparatorType)sendNewlineSeparatorType;
+            // update collection, invoke ui thread if necessary
+            ContextHelpers.InvokeIfNecessary(this.uiContext, (Action)delegate
+            {
             this.SentData = ReorderDataCollection(this.SentData, this.currentSentNewlineSeparatorType);
+            });
         }
     }
 
diff --git a/MultiTerm.Protocols/Serial/SerialProtocolSettingsViewModel.cs b/MultiTerm.Protocols/Serial/SerialProtocolSettingsViewModel.cs
index e79b671..28bb498 100644
--- a/MultiTerm.Protocols/Serial/SerialProtocolSettingsViewModel.cs
+++ b/MultiTerm.Protocols/Serial/SerialProtocolSettingsViewModel.cs
@@ -35,6 +35,11 @@ public partial class SerialProtocolSettingsViewModel : ProtocolSettingsViewModel
     private void ReloadComPorts()
     {
         this.ComPorts = SerialProtocol.GetPortNames();
+        // select first COM port, if none is selected yet and there are some available
+        if (String.IsNullOrEmpty(this.PortName) && this.ComPorts.Any())
+        {
+            this.PortName = this.ComPorts.First();
+        }
     }
 
     public SerialProtocolSettingsViewModel(IMessenger messenger) : base(messenger) 
diff --git a/MultiTerm.Wpf.CustomControl/MultiFormatTextBox/MultiFormatTextBox.cs b/MultiTerm.Wpf.CustomControl/MultiFormatTextBox/MultiFormatTextBox.cs
index 92b08a6..f201842 100644
--- a/MultiTerm.Wpf.CustomControl/MultiFormatTextBox/MultiFormatTextBox.cs
+++ b/MultiTerm.Wpf.CustomControl/MultiFormatTextBox/MultiFormatTextBox.cs
@@ -105,9 +105,14 @@ public class MultiFormatTextBox : Control
     private static void OnCurrentMultiFormatStringChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
     {
         // extract instance and guard null
-        // if (d is not MultiFormatTextBox mftb) { return; }
+        if (d is not MultiFormatTextBox mftb) { return; }
+        if (e.NewValue is not MultiFormatString newString) { return; }
 
-        // nothing to do
+        // new value is an empty string => clear
+        if(newString.FormatValuePairs.Count == 0)
+        {
+            mftb.richTextBox!.Document.Blocks.Clear();
+        }
     }
 
 
diff --git a/MultiTerm.Wpf/View/SendReceiveView.xaml b/MultiTerm.Wpf/View/SendReceiveView.xaml
index 0e30f20..fe74c05 100644
--- a/MultiTerm.Wpf/View/SendReceiveView.xaml
+++ b/MultiTerm.Wpf/View/SendReceiveView.xaml
@@ -71,7 +71,7 @@
                 <!-- Send text box -->
                 <DockPanel DockPanel.Dock="Top" LastChildFill="True">
                     <Button DockPanel.Dock="Right" Content="Send" Command="{Binding SendCommand}"/>
-                    <custom_controls:MultiFormatTextBox DockPanel.Dock="Left" CurrentMultiFormatString="{Binding Path=SendData, Mode=TwoWay}"></custom_controls:MultiFormatTextBox>
+                    <custom_controls:MultiFormatTextBox DockPanel.Dock="Left" CurrentMultiFormatString="{Binding Path=SendData, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"></custom_controls:MultiFormatTextBox>
                 </DockPanel>
                 <Separator/>
                 <TextBox DockPanel.Dock="Bottom" Text="{Binding SentData}">
diff --git a/MultiTerm.Wpf/View/SettingsView/SerialSettingsView.xaml b/MultiTerm.Wpf/View/SettingsView/SerialSettingsView.xaml
index 427e56e..ac72c98 100644
--- a/MultiTerm.Wpf/View/SettingsView/SerialSettingsView.xaml
+++ b/MultiTerm.Wpf/View/SettingsView/SerialSettingsView.xaml
@@ -43,7 +43,7 @@
             </StackPanel.Resources>
             
             <Label Margin="10 0" VerticalAlignment="Center">Port: </Label>
-            <ComboBox Width="75" ItemsSource="{Binding Path=ComPorts}" SelectedItem="{Binding Path=PortName}"/>
+            <ComboBox Width="75" ItemsSource="{Binding Path=ComPorts}" SelectedItem="{Binding Path=PortName, Mode=TwoWay}"/>
             <Button Margin="5 0" Content="R" Command="{Binding ReloadComPortsCommand}" Width="25"/>
 
             <Label Margin="20 0 10 0" VerticalAlignment="Center">Baud Rate:</Label>