diff --git a/Terminal.Gui/Views/ComboBox.cs b/Terminal.Gui/Views/ComboBox.cs
index c26a340ed..4fb87d7e5 100644
--- a/Terminal.Gui/Views/ComboBox.cs
+++ b/Terminal.Gui/Views/ComboBox.cs
@@ -749,7 +749,7 @@ namespace Terminal.Gui {
 			}
 
 			SetValue (searchset [listview.SelectedItem]);
-			search.CursorPosition = search.Text.RuneCount;
+			search.CursorPosition = search.Text.ConsoleWidth;
 			Search_Changed (search.Text);
 			OnOpenSelectedItem ();
 			Reset (keepSearchText: true);
@@ -825,7 +825,12 @@ namespace Terminal.Gui {
 				}
 			}
 
-			ShowList ();
+			if (HasFocus) {
+				ShowList ();
+			} else if (autoHide) {
+				isShow = false;
+				HideList ();
+			}
 		}
 
 		/// <summary>
diff --git a/Terminal.Gui/Windows/FileDialog.cs b/Terminal.Gui/Windows/FileDialog.cs
index 53e37558e..b57a01e05 100644
--- a/Terminal.Gui/Windows/FileDialog.cs
+++ b/Terminal.Gui/Windows/FileDialog.cs
@@ -656,12 +656,17 @@ namespace Terminal.Gui {
 				X = Pos.Right (nameEntry) + 2,
 				Y = Pos.Top (nameEntry),
 				Width = Dim.Fill (1),
-				Height = allowedTypes != null ? allowedTypes.Count + 1 : 1,
+				Height = SetComboBoxHeight (allowedTypes),
 				Text = allowedTypes?.Count > 0 ? allowedTypes [0] : string.Empty,
-				ReadOnly = true
+				SelectedItem = allowedTypes?.Count > 0 ? 0 : -1,
+				ReadOnly = true,
+				HideDropdownListOnClick = true
 			};
 			cmbAllowedTypes.SetSource (allowedTypes ?? new List<string> ());
-			cmbAllowedTypes.OpenSelectedItem += (e) => AllowedFileTypes = cmbAllowedTypes.Text.ToString ().Split (';');
+			cmbAllowedTypes.OpenSelectedItem += (e) => {
+				dirListView.AllowedFileTypes = cmbAllowedTypes.Text.ToString ().Split (';');
+				dirListView.Reload ();
+			};
 			Add (cmbAllowedTypes);
 
 			dirListView = new DirListView (this) {
@@ -673,7 +678,7 @@ namespace Terminal.Gui {
 			DirectoryPath = Path.GetFullPath (Environment.CurrentDirectory);
 			Add (dirListView);
 
-			AllowedFileTypes = cmbAllowedTypes.Text.ToString ().Split (';');
+			AllowedFileTypes = allowedTypes?.Count > 0 ? allowedTypes?.ToArray () : null;
 			dirListView.DirectoryChanged = (dir) => { nameEntry.Text = ustring.Empty; dirEntry.Text = dir; };
 			dirListView.FileChanged = (file) => nameEntry.Text = file == ".." ? "" : file;
 			dirListView.SelectedChanged = (file) => nameEntry.Text = file.Item1 == ".." ? "" : file.Item1;
@@ -738,6 +743,11 @@ namespace Terminal.Gui {
 			}
 		}
 
+		private static int SetComboBoxHeight (List<string> allowedTypes)
+		{
+			return allowedTypes != null ? Math.Min (allowedTypes.Count + 1, 8) : 8;
+		}
+
 		internal bool canceled;
 
 		///<inheritdoc/>
@@ -821,13 +831,22 @@ namespace Terminal.Gui {
 			}
 		}
 
+		private string [] allowedFileTypes;
+
 		/// <summary>
 		/// The array of filename extensions allowed, or null if all file extensions are allowed.
 		/// </summary>
 		/// <value>The allowed file types.</value>
 		public string [] AllowedFileTypes {
-			get => dirListView.AllowedFileTypes;
-			set => dirListView.AllowedFileTypes = value;
+			get => allowedFileTypes;
+			set {
+				allowedFileTypes = value;
+				var selected = cmbAllowedTypes.SelectedItem;
+				cmbAllowedTypes.SetSource (value);
+				cmbAllowedTypes.SelectedItem = selected > -1 ? selected : 0;
+				SetComboBoxHeight (value?.ToList ());
+				dirListView.AllowedFileTypes = value [cmbAllowedTypes.SelectedItem].Split (';');
+			}
 		}
 
 		/// <summary>
diff --git a/UICatalog/Scenarios/CsvEditor.cs b/UICatalog/Scenarios/CsvEditor.cs
index fe30bdf87..46de4670a 100644
--- a/UICatalog/Scenarios/CsvEditor.cs
+++ b/UICatalog/Scenarios/CsvEditor.cs
@@ -385,8 +385,9 @@ namespace UICatalog.Scenarios {
 
 		private void Open ()
 		{
-			var ofd = new FileDialog ("Select File", "Open", "File", "Select a CSV file to open (does not support newlines, escaping etc)");
-			ofd.AllowedFileTypes = new string [] { ".csv" };
+			var ofd = new FileDialog ("Select File", "Open", "File", "Select a CSV file to open (does not support newlines, escaping etc)") {
+				AllowedFileTypes = new string [] { ".csv" }
+			};
 
 			Application.Run (ofd);
 
diff --git a/UICatalog/Scenarios/Editor.cs b/UICatalog/Scenarios/Editor.cs
index 8bc930389..6eda3a686 100644
--- a/UICatalog/Scenarios/Editor.cs
+++ b/UICatalog/Scenarios/Editor.cs
@@ -365,7 +365,7 @@ namespace UICatalog.Scenarios {
 			if (!CanCloseFile ()) {
 				return;
 			}
-			var aTypes = new List<string> () { ".txt;.bin;.xml;.json", ".txt", ".bin", ".xml", ".*" };
+			var aTypes = new List<string> () { ".txt;.bin;.xml;.json", ".txt", ".bin", ".xml", ".json", ".*" };
 			var d = new OpenDialog ("Open", "Choose the path where to open the file.", aTypes) { AllowsMultipleSelection = false };
 			Application.Run (d);