--- a/layout/base/AccessibleCaretManager.cpp
+++ b/layout/base/AccessibleCaretManager.cpp
@@ -73,18 +73,19 @@ std::ostream& operator<<(std::ostream& a
 #undef AC_PROCESS_ENUM_TO_STREAM
 
 /* static */ bool
 AccessibleCaretManager::sSelectionBarEnabled = false;
 /* static */ bool
 AccessibleCaretManager::sCaretShownWhenLongTappingOnEmptyContent = false;
 /* static */ bool
 AccessibleCaretManager::sCaretsAlwaysTilt = false;
-/* static */ bool
-AccessibleCaretManager::sCaretsScriptUpdates = false;
+/* static */ int32_t
+AccessibleCaretManager::sCaretsScriptUpdates =
+    AccessibleCaretManager::kScriptAlwaysHide;
 /* static */ bool
 AccessibleCaretManager::sCaretsAllowDraggingAcrossOtherCaret = true;
 /* static */ bool
 AccessibleCaretManager::sHapticFeedback = false;
 /* static */ bool
 AccessibleCaretManager::sExtendSelectionForPhoneNumber = false;
 /* static */ bool
 AccessibleCaretManager::sHideCaretsForMouseInput = true;
@@ -102,18 +103,18 @@ AccessibleCaretManager::AccessibleCaretM
   static bool addedPrefs = false;
   if (!addedPrefs) {
     Preferences::AddBoolVarCache(&sSelectionBarEnabled,
                                  "layout.accessiblecaret.bar.enabled");
     Preferences::AddBoolVarCache(&sCaretShownWhenLongTappingOnEmptyContent,
       "layout.accessiblecaret.caret_shown_when_long_tapping_on_empty_content");
     Preferences::AddBoolVarCache(&sCaretsAlwaysTilt,
                                  "layout.accessiblecaret.always_tilt");
-    Preferences::AddBoolVarCache(&sCaretsScriptUpdates,
-      "layout.accessiblecaret.allow_script_change_updates");
+    Preferences::AddIntVarCache(&sCaretsScriptUpdates,
+      "layout.accessiblecaret.script_change_update_mode");
     Preferences::AddBoolVarCache(&sCaretsAllowDraggingAcrossOtherCaret,
       "layout.accessiblecaret.allow_dragging_across_other_caret", true);
     Preferences::AddBoolVarCache(&sHapticFeedback,
                                  "layout.accessiblecaret.hapticfeedback");
     Preferences::AddBoolVarCache(&sExtendSelectionForPhoneNumber,
       "layout.accessiblecaret.extend_selection_for_phone_number");
     Preferences::AddBoolVarCache(&sHideCaretsForMouseInput,
       "layout.accessiblecaret.hide_carets_for_mouse_input");
@@ -149,21 +150,22 @@ AccessibleCaretManager::OnSelectionChang
   // eSetSelection events from the Fennec widget IME can be generated
   // by autoSuggest / autoCorrect composition changes, or by TYPE_REPLACE_TEXT
   // actions, either positioning cursor for text insert, or selecting
   // text-to-be-replaced. None should affect AccessibleCaret visibility.
   if (aReason & nsISelectionListener::IME_REASON) {
     return NS_OK;
   }
 
-  // Move the cursor by Javascript / or unknown internal.
+  // Move the cursor by JavaScript or unknown internal call.
   if (aReason == nsISelectionListener::NO_REASON) {
-    // Update visible carets, if javascript changes are allowed.
-    if (sCaretsScriptUpdates &&
-        (mFirstCaret->IsLogicallyVisible() || mSecondCaret->IsLogicallyVisible())) {
+    if (sCaretsScriptUpdates == kScriptAlwaysShow ||
+        (sCaretsScriptUpdates == kScriptUpdateVisible &&
+         (mFirstCaret->IsLogicallyVisible() ||
+          mSecondCaret->IsLogicallyVisible()))) {
         UpdateCarets();
         return NS_OK;
     }
     // Default for NO_REASON is to make hidden.
     HideCarets();
     return NS_OK;
   }
 

--- a/layout/base/AccessibleCaretManager.h
+++ b/layout/base/AccessibleCaretManager.h
@@ -344,20 +344,29 @@ protected:
   // which is based on the emptiness of the content, into something more
   // heuristic. See UpdateCaretsForCursorMode() for the details.
   static bool sCaretShownWhenLongTappingOnEmptyContent;
 
   // Preference to make carets always tilt in selection mode. By default, the
   // carets become tilt only when they are overlapping.
   static bool sCaretsAlwaysTilt;
 
-  // By default, javascript content selection changes closes AccessibleCarets and
-  // UI interactions. Optionally, we can try to maintain the active UI, keeping
-  // carets and ActionBar available.
-  static bool sCaretsScriptUpdates;
+  enum ScriptUpdateMode : int32_t {
+    // By default, always hide carets for selection changes due to JS calls.
+    kScriptAlwaysHide,
+    // Update any visible carets for selection changes due to JS calls,
+    // but don't show carets if carets are hidden.
+    kScriptUpdateVisible,
+    // Always show carets for selection changes due to JS calls.
+    kScriptAlwaysShow
+  };
+
+  // Preference to indicate how to update carets for selection changes due to
+  // JS calls, as one of the ScriptUpdateMode constants.
+  static int32_t sCaretsScriptUpdates;
 
   // Preference to allow one caret to be dragged across the other caret without
   // any limitation. When set to false, one caret cannot be dragged across the
   // other one.
   static bool sCaretsAllowDraggingAcrossOtherCaret;
 
   // AccessibleCaret pref for haptic feedback behaviour on longPress.
   static bool sHapticFeedback;

--- a/mobile/android/app/mobile.js
+++ b/mobile/android/app/mobile.js
@@ -776,19 +776,19 @@ pref("layout.accessiblecaret.height", "2
 pref("layout.accessiblecaret.margin-left", "-11.5");
 
 // Android needs to show the caret when long tapping on an empty content.
 pref("layout.accessiblecaret.caret_shown_when_long_tapping_on_empty_content", true);
 
 // Androids carets are always tilt to match the text selection guideline.
 pref("layout.accessiblecaret.always_tilt", true);
 
-// Selection change notifications generated by Javascript changes
-// update active AccessibleCarets / UI interactions.
-pref("layout.accessiblecaret.allow_script_change_updates", true);
+// Update any visible carets for selection changes due to JS calls,
+// but don't show carets if carets are hidden.
+pref("layout.accessiblecaret.script_change_update_mode", 1);
 
 // Optionally provide haptic feedback on longPress selection events.
 pref("layout.accessiblecaret.hapticfeedback", true);
 
 // Initial text selection on long-press is enhanced to provide
 // a smarter phone-number selection for direct-dial ActionBar action.
 pref("layout.accessiblecaret.extend_selection_for_phone_number", true);
 

--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -5466,19 +5466,21 @@ pref("layout.accessiblecaret.caret_shown
 
 // Simulate long tap to select words on the platforms where APZ is not enabled
 // or long tap events does not fired by APZ.
 pref("layout.accessiblecaret.use_long_tap_injector", false);
 
 // By default, carets become tilt only when they are overlapping.
 pref("layout.accessiblecaret.always_tilt", false);
 
-// Selection change notifications generated by Javascript hide
-// AccessibleCarets and close UI interaction by default.
-pref("layout.accessiblecaret.allow_script_change_updates", false);
+// 0 = by default, always hide carets for selection changes due to JS calls.
+// 1 = update any visible carets for selection changes due to JS calls,
+//     but don't show carets if carets are hidden.
+// 2 = always show carets for selection changes due to JS calls.
+pref("layout.accessiblecaret.script_change_update_mode", 0);
 
 // Allow one caret to be dragged across the other caret without any limitation.
 // This matches the built-in convention for all desktop platforms.
 pref("layout.accessiblecaret.allow_dragging_across_other_caret", true);
 
 // Optionally provide haptic feedback on longPress selection events.
 pref("layout.accessiblecaret.hapticfeedback", false);