diff --git a/src/gui/src/UI/UIWindowAppFeedback.js b/src/gui/src/UI/UIWindowAppFeedback.js
index 66f789213..8fba932a4 100644
--- a/src/gui/src/UI/UIWindowAppFeedback.js
+++ b/src/gui/src/UI/UIWindowAppFeedback.js
@@ -142,7 +142,13 @@ async function UIWindowAppFeedback (options) {
         $overlay.on('mousedown', (e) => {
             if ( e.target === $overlay.get(0) && ! sending ) close();
         });
-        $overlay.find('.app-feedback-x, .app-feedback-close-btn, .app-feedback-cancel-btn').on('click', close);
+        // Same in-flight gate as Escape/backdrop: closing while the POST is
+        // pending would settle false for a submission that still lands
+        // server-side — the developer gets the email while the app is told
+        // nothing was sent.
+        $overlay.find('.app-feedback-x, .app-feedback-close-btn, .app-feedback-cancel-btn').on('click', () => {
+            if ( ! sending ) close();
+        });
 
         $overlay.find('.app-feedback-message').on('input', function () {
             $overlay.find('.app-feedback-counter').text(`${this.value.length} / ${MESSAGE_MAX_LENGTH}`);
@@ -155,6 +161,7 @@ async function UIWindowAppFeedback (options) {
             if ( ! message || sending ) return;
             sending = true;
             $btn.prop('disabled', true);
+            $overlay.find('.app-feedback-x, .app-feedback-cancel-btn').prop('disabled', true);
             $overlay.find('.app-feedback-error').hide();
             try {
                 const res = await fetch(`${window.api_origin}/app-feedback`, {
@@ -193,6 +200,7 @@ async function UIWindowAppFeedback (options) {
                 $overlay.find('.app-feedback-error').text(i18n('app_feedback_error')).show();
             } finally {
                 sending = false;
+                $overlay.find('.app-feedback-x, .app-feedback-cancel-btn').prop('disabled', false);
                 $overlay.find('.app-feedback-send-btn').prop('disabled',
                     settled || String($overlay.find('.app-feedback-message').val() || '').trim() === '');
             }
diff --git a/src/gui/src/css/dashboard.css b/src/gui/src/css/dashboard.css
index 20c0669cb..618704a1f 100644
--- a/src/gui/src/css/dashboard.css
+++ b/src/gui/src/css/dashboard.css
@@ -1619,7 +1619,7 @@ input.myapps-group-name:focus {
     height: 16px;
 }
 @media (hover: hover) {
-    .app-feedback-x:hover {
+    .app-feedback-x:hover:not(:disabled) {
         background: var(--afb-hover);
         color: var(--afb-fg);
     }
@@ -1727,7 +1727,7 @@ input.myapps-group-name:focus {
     transition: background-color 0.12s ease, opacity 0.12s ease, filter 0.12s ease;
 }
 @media (hover: hover) {
-    .app-feedback-btn:hover {
+    .app-feedback-btn:hover:not(:disabled) {
         background: var(--afb-hover);
     }
 }
@@ -1747,6 +1747,12 @@ input.myapps-group-name:focus {
     cursor: default;
     filter: none;
 }
+/* Cancel/X are disabled while a submit is in flight. */
+.app-feedback-btn:disabled,
+.app-feedback-x:disabled {
+    opacity: 0.5;
+    cursor: default;
+}
 
 .app-feedback-success {
     text-align: center;