Controlled TextInput doesn't work most of the time

change/react-native-windows-9aaace3c-20a8-4c24-90b2-d777742f65ba.json

@@ -0,0 +1,7 @@
+{
+  "type": "prerelease",
+  "comment": "If initial value is set, updated TextInput.value changes will not be reflected",
+  "packageName": "react-native-windows",
+  "email": "30809111+acoates-ms@users.noreply.github.com",
+  "dependentChangeType": "patch"
+}

vnext/Microsoft.ReactNative/Views/TextInputViewManager.cpp

@@ -133,14 +133,16 @@ class TextInputShadowNode : public ShadowNodeBase {
   void SetSelection(int64_t start, int64_t end);
   winrt::Shape FindCaret(xaml::DependencyObject element);
 
+  bool m_initialUpdateComplete = false;
   bool m_autoFocus = false;
   bool m_shouldClearTextOnFocus = false;
   bool m_shouldSelectTextOnFocus = false;
   bool m_contextMenuHidden = false;
   bool m_hideCaret = false;
   bool m_isTextBox = true;
-  winrt::Microsoft::ReactNative::JSValue m_placeholderTextColor;
   bool m_shouldClearTextOnSubmit = false;
+
+  winrt::Microsoft::ReactNative::JSValue m_placeholderTextColor;
   std::vector<HandledKeyboardEvent> m_submitKeyEvents{};
 
   // Javascripts is running in a different thread. If the typing is very fast,
@@ -175,6 +177,9 @@ void TextInputShadowNode::createView(const winrt::Microsoft::ReactNative::JSValu
 }
 
 void TextInputShadowNode::dispatchTextInputChangeEvent(winrt::hstring newText) {
+  if (!m_initialUpdateComplete) {
+    return;
+  }
   m_nativeEventCount++;
   folly::dynamic eventData = folly::dynamic::object("target", m_tag)("text", react::uwp::HstringToDynamic(newText))(
       "eventCount", m_nativeEventCount);
@@ -199,14 +204,20 @@ void TextInputShadowNode::registerEvents() {
   // another TextChanged event with correct event count.
   if (m_isTextBox) {
     m_passwordBoxPasswordChangingRevoker = {};
-    m_textBoxTextChangingRevoker = control.as<xaml::Controls::TextBox>().TextChanging(
-        winrt::auto_revoke, [=](auto &&, auto &&) { m_nativeEventCount++; });
+    m_textBoxTextChangingRevoker =
+        control.as<xaml::Controls::TextBox>().TextChanging(winrt::auto_revoke, [=](auto &&, auto &&) {
+          if (m_initialUpdateComplete)
+            m_nativeEventCount++;
+        });
   } else {
     m_textBoxTextChangingRevoker = {};
 
     if (control.try_as<xaml::Controls::IPasswordBox4>()) {
-      m_passwordBoxPasswordChangingRevoker = control.as<xaml::Controls::IPasswordBox4>().PasswordChanging(
-          winrt::auto_revoke, [=](auto &&, auto &&) { m_nativeEventCount++; });
+      m_passwordBoxPasswordChangingRevoker =
+          control.as<xaml::Controls::IPasswordBox4>().PasswordChanging(winrt::auto_revoke, [=](auto &&, auto &&) {
+            if (m_initialUpdateComplete)
+              m_nativeEventCount++;
+          });
     }
   }
 
@@ -673,6 +684,7 @@ void TextInputShadowNode::updateProperties(winrt::Microsoft::ReactNative::JSValu
   }
 
   m_updating = false;
+  m_initialUpdateComplete = true;
 }
 
 void TextInputShadowNode::SetText(const winrt::Microsoft::ReactNative::JSValue &text) {

vnext/src/Libraries/Components/TextInput/TextInput.windows.js

@@ -1229,6 +1229,7 @@ function InternalTextInput(props: Props): React.Node {
         ref={_setNativeRef}
         {...props}
         dataDetectorTypes={props.dataDetectorTypes}
+        mostRecentEventCount={mostRecentEventCount}
         onBlur={_onBlur}
         onChange={_onChange}
         onContentSizeChange={props.onContentSizeChange}