Ensure the component runs and don't replace UDIs on saving since its not necessary

src/Umbraco.Web/Compose/BlockEditorComponent.cs

@@ -27,7 +27,13 @@ namespace Umbraco.Web.Compose
 
         public void Terminate() => _handler?.Dispose();
 
-        private string ReplaceBlockListUdis(string rawJson, bool onlyMissingUdis) => ReplaceBlockListUdis(rawJson, null);
+        private string ReplaceBlockListUdis(string rawJson, bool onlyMissingUdis)
+        {
+            // the block editor doesn't ever have missing UDIs so when this is true there's nothing to process
+            if (onlyMissingUdis) return rawJson;
+
+            return ReplaceBlockListUdis(rawJson, null);
+        }
 
         // internal for tests
         internal string ReplaceBlockListUdis(string rawJson, Func<Guid> createGuid = null)

src/Umbraco.Web/Compose/BlockEditorComposer.cs

@@ -7,6 +7,6 @@ namespace Umbraco.Web.Compose
     /// A composer for Block editors to run a component
     /// </summary>
     [RuntimeLevel(MinLevel = RuntimeLevel.Run)]
-    public class BlockEditorComposer : ComponentComposer<NestedContentPropertyComponent>, ICoreComposer
+    public class BlockEditorComposer : ComponentComposer<BlockEditorComponent>, ICoreComposer
     { }
 }