diff --git a/src/Umbraco.Core/Serialization/AutoInterningStringKeyCaseInsensitiveDictionaryConverter.cs b/src/Umbraco.Core/Serialization/AutoInterningStringKeyCaseInsensitiveDictionaryConverter.cs
index 2076462f0c..f40b4b9f10 100644
--- a/src/Umbraco.Core/Serialization/AutoInterningStringKeyCaseInsensitiveDictionaryConverter.cs
+++ b/src/Umbraco.Core/Serialization/AutoInterningStringKeyCaseInsensitiveDictionaryConverter.cs
@@ -7,7 +7,7 @@ using Newtonsoft.Json.Converters;
 namespace Umbraco.Core.Serialization
 {
     /// <summary>
-    /// When applied to a dictionary with a string key, will ensure the deserialized string keys are interned 
+    /// When applied to a dictionary with a string key, will ensure the deserialized string keys are interned
     /// </summary>
     /// <typeparam name="TValue"></typeparam>
     /// <remarks>
@@ -26,7 +26,7 @@ namespace Umbraco.Core.Serialization
         {
             if (reader.TokenType == JsonToken.StartObject)
             {
-                var dictionary = new Dictionary<string, TValue>();
+                var dictionary = Create(objectType);
                 while (reader.Read())
                 {
                     switch (reader.TokenType)
diff --git a/src/Umbraco.Web.UI.Client/src/common/services/blockeditormodelobject.service.js b/src/Umbraco.Web.UI.Client/src/common/services/blockeditormodelobject.service.js
index ccf6d395f6..cb06218618 100644
--- a/src/Umbraco.Web.UI.Client/src/common/services/blockeditormodelobject.service.js
+++ b/src/Umbraco.Web.UI.Client/src/common/services/blockeditormodelobject.service.js
@@ -608,6 +608,12 @@
                             return null;
                         }
 
+                        // the Settings model has been changed to a new Element Type.
+                        // we need to update the settingsData with the new Content Type key
+                        if (settingsData.contentTypeKey !== settingsScaffold.contentTypeKey) {
+                            settingsData.contentTypeKey = settingsScaffold.contentTypeKey;
+                        }
+
                         blockObject.settingsData = settingsData;
 
                         // make basics from scaffold
diff --git a/src/Umbraco.Web/PublishedCache/NuCache/DataSource/ContentCacheDataModel.cs b/src/Umbraco.Web/PublishedCache/NuCache/DataSource/ContentCacheDataModel.cs
index 40acdfdb55..de49581730 100644
--- a/src/Umbraco.Web/PublishedCache/NuCache/DataSource/ContentCacheDataModel.cs
+++ b/src/Umbraco.Web/PublishedCache/NuCache/DataSource/ContentCacheDataModel.cs
@@ -17,11 +17,13 @@ namespace Umbraco.Web.PublishedCache.NuCache.DataSource
         [DataMember(Order = 0)]
         [JsonProperty("pd")]
         [JsonConverter(typeof(AutoInterningStringKeyCaseInsensitiveDictionaryConverter<PropertyData[]>))]
+        [MessagePackFormatter(typeof(MessagePackAutoInterningStringKeyCaseInsensitiveDictionaryFormatter<PropertyData[]>))]
         public Dictionary<string, PropertyData[]> PropertyData { get; set; }
 
         [DataMember(Order = 1)]
         [JsonProperty("cd")]
         [JsonConverter(typeof(AutoInterningStringKeyCaseInsensitiveDictionaryConverter<CultureVariation>))]
+        [MessagePackFormatter(typeof(MessagePackAutoInterningStringKeyCaseInsensitiveDictionaryFormatter<CultureVariation>))]
         public Dictionary<string, CultureVariation> CultureData { get; set; }
 
         [DataMember(Order = 2)]
diff --git a/src/Umbraco.Web/PublishedCache/NuCache/DataSource/MessagePackAutoInterningStringKeyCaseInsensitiveDictionaryFormatter.cs b/src/Umbraco.Web/PublishedCache/NuCache/DataSource/MessagePackAutoInterningStringKeyCaseInsensitiveDictionaryFormatter.cs
new file mode 100644
index 0000000000..24691497bc
--- /dev/null
+++ b/src/Umbraco.Web/PublishedCache/NuCache/DataSource/MessagePackAutoInterningStringKeyCaseInsensitiveDictionaryFormatter.cs
@@ -0,0 +1,39 @@
+using System;
+using System.Collections.Generic;
+using MessagePack;
+using MessagePack.Formatters;
+
+namespace Umbraco.Web.PublishedCache.NuCache.DataSource
+{
+    /// <summary>
+    /// A messagepack formatter (deserializer) for a string key dictionary that uses OrdinalIgnoreCase for the key string comparison
+    /// </summary>
+    /// <typeparam name="TValue"></typeparam>
+    public sealed class MessagePackAutoInterningStringKeyCaseInsensitiveDictionaryFormatter<TValue> : DictionaryFormatterBase<string, TValue, Dictionary<string, TValue>, Dictionary<string, TValue>.Enumerator, Dictionary<string, TValue>>
+    {
+        protected override void Add(Dictionary<string, TValue> collection, int index, string key, TValue value, MessagePackSerializerOptions options)
+        {
+            string.Intern(key);
+            collection.Add(key, value);
+        }
+
+        protected override Dictionary<string, TValue> Complete(Dictionary<string, TValue> intermediateCollection)
+        {
+            return intermediateCollection;
+        }
+
+
+        protected override Dictionary<string, TValue>.Enumerator GetSourceEnumerator(Dictionary<string, TValue> source)
+        {
+            return source.GetEnumerator();
+        }
+
+        protected override Dictionary<string, TValue> Create(int count, MessagePackSerializerOptions options)
+        {
+            return new Dictionary<string, TValue>(count, StringComparer.OrdinalIgnoreCase);
+        }
+    }
+}
+
+
+
diff --git a/src/Umbraco.Web/Umbraco.Web.csproj b/src/Umbraco.Web/Umbraco.Web.csproj
index 2340228eae..5f6ab67a42 100644
--- a/src/Umbraco.Web/Umbraco.Web.csproj
+++ b/src/Umbraco.Web/Umbraco.Web.csproj
@@ -297,6 +297,7 @@
     <Compile Include="PublishedCache\NuCache\DataSource\JsonContentNestedDataSerializer.cs" />
     <Compile Include="PublishedCache\NuCache\DataSource\JsonContentNestedDataSerializerFactory.cs" />
     <Compile Include="PublishedCache\NuCache\DataSource\LazyCompressedString.cs" />
+    <Compile Include="PublishedCache\NuCache\DataSource\MessagePackAutoInterningStringKeyCaseInsensitiveDictionaryFormatter.cs" />
     <Compile Include="PublishedCache\NuCache\DataSource\MsgPackContentNestedDataSerializer.cs" />
     <Compile Include="PropertyEditors\Validation\ComplexEditorElementTypeValidationResult.cs" />
     <Compile Include="PropertyEditors\Validation\ComplexEditorPropertyTypeValidationResult.cs" />