diff --git a/src/LiveDevelopment/BrowserScripts/LiveDevProtocolRemote.js b/src/LiveDevelopment/BrowserScripts/LiveDevProtocolRemote.js
index 9f97dc165d..87d8e70b46 100644
--- a/src/LiveDevelopment/BrowserScripts/LiveDevProtocolRemote.js
+++ b/src/LiveDevelopment/BrowserScripts/LiveDevProtocolRemote.js
@@ -373,6 +373,7 @@
         const lpFn = registeredPhoenixCommFns[fnName];
         if(!lpFn) {
             console.error(`PhoenixComm: No such LP function ${fnName}`);
+            return;
         }
         try {
             const response = lpFn(paramObj);
@@ -390,6 +391,12 @@
     let lpCommReady = false;
     const pendingExecPromises = new Map();
     let queuedExecRequests = [];         // array of { fnName, paramObj, fnExecID }
+    // A pending execPhoenixFn is only ever settled by a response message, so if
+    // the editor disconnects mid-call the promise would hang forever (and any
+    // awaiting caller — e.g. a styles-bar session reset — stalls). Reject after
+    // this long instead; it's far beyond any real round-trip, so it only fires
+    // on a genuine hang, never on a slow-but-legitimate operation.
+    const PHOENIX_FN_TIMEOUT_MS = 30000;
 
     /**
      * Sends immediately if ready, else queues for later replay.
@@ -425,7 +432,13 @@
         execPhoenixFn: function (fnName, paramObj) {
             return new Promise((resolve, reject) => {
                 const fnExecID = currentFnExecID++;
-                pendingExecPromises.set(fnExecID, { resolve, reject });
+                const timer = setTimeout(function () {
+                    if (pendingExecPromises.has(fnExecID)) {
+                        pendingExecPromises.delete(fnExecID);
+                        reject(new Error(`execPhoenixFn timed out: ${fnName}`));
+                    }
+                }, PHOENIX_FN_TIMEOUT_MS);
+                pendingExecPromises.set(fnExecID, { resolve, reject, timer });
                 _sendOrQueueExec({
                     execFnName: fnName,
                     paramObj,
@@ -445,9 +458,15 @@
     function _onPhoenixExecResponse(fnName, fnExecID, resolveWith, rejectWith) {
         const pendingPromise = pendingExecPromises.get(fnExecID);
         if(!pendingPromise) {
+            // already settled (e.g. by the timeout) or an unknown id — bail
+            // rather than dereference undefined and throw in the message handler
             console.error(`execPhoenixFn: No response promise found! for ${fnName}: ${fnExecID}`);
+            return;
         }
         pendingExecPromises.delete(fnExecID);
+        if (pendingPromise.timer) {
+            clearTimeout(pendingPromise.timer);
+        }
         if(rejectWith) {
             pendingPromise.reject(rejectWith);
         } else {
diff --git a/src/LiveDevelopment/BrowserScripts/RemoteFunctions.js b/src/LiveDevelopment/BrowserScripts/RemoteFunctions.js
index b79eae6201..3c6c410764 100644
--- a/src/LiveDevelopment/BrowserScripts/RemoteFunctions.js
+++ b/src/LiveDevelopment/BrowserScripts/RemoteFunctions.js
@@ -72,6 +72,9 @@ function RemoteFunctions(config = {}) {
         // called when an item is selected from the more options dropdown
         "handleDropdownClick",
         "updateContent", // in-place content refresh for control box etc. after drag
+        // a DOM edit changed the selected element's attributes or rebuilt its node —
+        // refresh shown UI in place; must never resurrect dismissed UI
+        "onSelectedElementMutated",
         "reRegisterEventHandlers",
         "handleClick", // handle click on an icon in the tool box.
         // when escape key is presses in the editor, we may need to dismiss the live edit boxes.
@@ -1201,6 +1204,7 @@ function RemoteFunctions(config = {}) {
             targetElement,
             childElement,
             self = this;
+        let selectedElementMutated = false;
 
         this.rememberedNodes = {};
 
@@ -1235,9 +1239,15 @@ function RemoteFunctions(config = {}) {
             case "attrChange":
             case "attrAdd":
                 targetElement.setAttribute(edit.attribute, self._parseEntities(edit.value));
+                if (targetElement === previouslySelectedElement) {
+                    selectedElementMutated = true;
+                }
                 break;
             case "attrDelete":
                 targetElement.removeAttribute(edit.attribute);
+                if (targetElement === previouslySelectedElement) {
+                    selectedElementMutated = true;
+                }
                 break;
             case "elementDelete":
                 if (targetElement.remove) {
@@ -1372,9 +1382,22 @@ function RemoteFunctions(config = {}) {
                         SHARED_STATE._editorBox.element = freshElement;
                     }
                     redrawEverything();
+                    selectedElementMutated = true;
                 }
             }
         }
+
+        // neither path above refreshes selection-anchored UI CONTENT (the paths
+        // only reposition / re-point element refs), so content rendered at
+        // selection time — e.g. the control box's tag/#id/.classes line — would
+        // stay stale after the selected element's markup changed
+        if (selectedElementMutated && previouslySelectedElement && previouslySelectedElement.isConnected) {
+            getAllToolHandlers().forEach(function (handler) {
+                if (handler.onSelectedElementMutated) {
+                    handler.onSelectedElementMutated(previouslySelectedElement);
+                }
+            });
+        }
     };
 
     function applyDOMEdits(edits) {