diff --git a/ui/app/(prowler)/lighthouse/_components/ai-elements/chain-of-thought.tsx b/ui/app/(prowler)/lighthouse/_components/ai-elements/chain-of-thought.tsx
index 35e0539b4a..474fed577c 100644
--- a/ui/app/(prowler)/lighthouse/_components/ai-elements/chain-of-thought.tsx
+++ b/ui/app/(prowler)/lighthouse/_components/ai-elements/chain-of-thought.tsx
@@ -59,11 +59,19 @@ export function ChainOfThought({
 
   const chainOfThoughtContext = { isOpen, setIsOpen };
 
+  // One Collapsible root wraps both header and content so CollapsibleTrigger and
+  // CollapsibleContent share Radix's ARIA/id wiring; the context only carries
+  // `isOpen` for presentational bits like the header chevron.
   return (
     <ChainOfThoughtContext.Provider value={chainOfThoughtContext}>
-      <div className={cn("not-prose w-full space-y-4", className)} {...props}>
+      <Collapsible
+        open={isOpen}
+        onOpenChange={setIsOpen}
+        className={cn("not-prose w-full space-y-4", className)}
+        {...props}
+      >
         {children}
-      </div>
+      </Collapsible>
     </ChainOfThoughtContext.Provider>
   );
 }
@@ -77,37 +85,42 @@ export function ChainOfThoughtHeader({
   children,
   ...props
 }: ChainOfThoughtHeaderProps) {
-  const { isOpen, setIsOpen } = useChainOfThought();
+  const { isOpen } = useChainOfThought();
 
   return (
-    <Collapsible onOpenChange={setIsOpen} open={isOpen}>
-      <CollapsibleTrigger
+    <CollapsibleTrigger
+      className={cn(
+        "text-muted-foreground hover:text-foreground flex w-full items-center gap-2 text-sm transition-colors",
+        className,
+      )}
+      {...props}
+    >
+      <BrainIcon className="size-4" />
+      <span className="flex-1 text-left">{children ?? "Chain of Thought"}</span>
+      <ChevronDownIcon
         className={cn(
-          "text-muted-foreground hover:text-foreground flex w-full items-center gap-2 text-sm transition-colors",
-          className,
+          "size-4 transition-transform",
+          isOpen ? "rotate-180" : "rotate-0",
         )}
-        {...props}
-      >
-        <BrainIcon className="size-4" />
-        <span className="flex-1 text-left">
-          {children ?? "Chain of Thought"}
-        </span>
-        <ChevronDownIcon
-          className={cn(
-            "size-4 transition-transform",
-            isOpen ? "rotate-180" : "rotate-0",
-          )}
-        />
-      </CollapsibleTrigger>
-    </Collapsible>
+      />
+    </CollapsibleTrigger>
   );
 }
 
+export const CHAIN_OF_THOUGHT_STATUS = {
+  COMPLETE: "complete",
+  ACTIVE: "active",
+  PENDING: "pending",
+} as const;
+
+export type ChainOfThoughtStatus =
+  (typeof CHAIN_OF_THOUGHT_STATUS)[keyof typeof CHAIN_OF_THOUGHT_STATUS];
+
 export type ChainOfThoughtStepProps = ComponentProps<"div"> & {
   icon?: LucideIcon;
   label: ReactNode;
   description?: ReactNode;
-  status?: "complete" | "active" | "pending";
+  status?: ChainOfThoughtStatus;
 };
 
 export function ChainOfThoughtStep({
@@ -115,7 +128,7 @@ export function ChainOfThoughtStep({
   icon: Icon = DotIcon,
   label,
   description,
-  status = "complete",
+  status = CHAIN_OF_THOUGHT_STATUS.COMPLETE,
   children,
   ...props
 }: ChainOfThoughtStepProps) {
@@ -191,21 +204,17 @@ export function ChainOfThoughtContent({
   children,
   ...props
 }: ChainOfThoughtContentProps) {
-  const { isOpen } = useChainOfThought();
-
   return (
-    <Collapsible open={isOpen}>
-      <CollapsibleContent
-        className={cn(
-          "mt-2 space-y-3",
-          "data-[state=closed]:fade-out-0 data-[state=closed]:slide-out-to-top-2 data-[state=open]:slide-in-from-top-2 text-popover-foreground data-[state=closed]:animate-out data-[state=open]:animate-in outline-none",
-          className,
-        )}
-        {...props}
-      >
-        {children}
-      </CollapsibleContent>
-    </Collapsible>
+    <CollapsibleContent
+      className={cn(
+        "mt-2 space-y-3",
+        "data-[state=closed]:fade-out-0 data-[state=closed]:slide-out-to-top-2 data-[state=open]:slide-in-from-top-2 text-popover-foreground data-[state=closed]:animate-out data-[state=open]:animate-in outline-none",
+        className,
+      )}
+      {...props}
+    >
+      {children}
+    </CollapsibleContent>
   );
 }
 
diff --git a/ui/app/(prowler)/lighthouse/_components/ai-elements/conversation.tsx b/ui/app/(prowler)/lighthouse/_components/ai-elements/conversation.tsx
index ec96807893..f1adfa3689 100644
--- a/ui/app/(prowler)/lighthouse/_components/ai-elements/conversation.tsx
+++ b/ui/app/(prowler)/lighthouse/_components/ai-elements/conversation.tsx
@@ -41,7 +41,10 @@ export const ConversationContent = ({
   const { contentRef, scrollRef } = context;
 
   return (
-    <div ref={scrollRef} className={cn("h-full w-full", scrollClassName)}>
+    <div
+      ref={scrollRef}
+      className={cn("h-full min-h-0 w-full overflow-y-auto", scrollClassName)}
+    >
       <div
         ref={contentRef}
         className={cn("flex flex-col gap-8 p-4", className)}
diff --git a/ui/app/(prowler)/lighthouse/_components/chat/composer.tsx b/ui/app/(prowler)/lighthouse/_components/chat/composer.tsx
index 1551c9ed2d..6ae0b468c8 100644
--- a/ui/app/(prowler)/lighthouse/_components/chat/composer.tsx
+++ b/ui/app/(prowler)/lighthouse/_components/chat/composer.tsx
@@ -119,7 +119,13 @@ function ChatComposer({
         textareaSize="lg"
         className="min-h-[104px] flex-1"
         onKeyDown={(event) => {
-          if (event.key === "Enter" && !event.shiftKey) {
+          // Ignore Enter while an IME composition is active so confirming an
+          // East Asian candidate doesn't submit the message prematurely.
+          if (
+            event.key === "Enter" &&
+            !event.shiftKey &&
+            !event.nativeEvent.isComposing
+          ) {
             event.preventDefault();
             void onSubmitText(input);
           }
diff --git a/ui/app/(prowler)/lighthouse/_components/navigation/lighthouse-v2-sidebar-chat.tsx b/ui/app/(prowler)/lighthouse/_components/navigation/lighthouse-v2-sidebar-chat.tsx
index c08b6ec940..1ffa980b8e 100644
--- a/ui/app/(prowler)/lighthouse/_components/navigation/lighthouse-v2-sidebar-chat.tsx
+++ b/ui/app/(prowler)/lighthouse/_components/navigation/lighthouse-v2-sidebar-chat.tsx
@@ -31,9 +31,14 @@ export function LighthouseV2SidebarChat({ isOpen }: { isOpen: boolean }) {
   const [search, setSearch] = useState("");
 
   const refreshSessions = async () => {
-    const result = await getLighthouseV2Sessions();
-    if ("data" in result) {
-      setSessions(result.data);
+    try {
+      const result = await getLighthouseV2Sessions();
+      if ("data" in result) {
+        setSessions(result.data);
+      }
+    } catch {
+      // Best-effort refresh: swallow transport-level failures so a rejected
+      // server action never escapes the mount effect as an unhandled error.
     }
   };
 
@@ -52,11 +57,15 @@ export function LighthouseV2SidebarChat({ isOpen }: { isOpen: boolean }) {
   };
 
   const handleArchiveSession = async (sessionId: string) => {
-    const result = await archiveLighthouseV2Session(sessionId);
-    if ("data" in result) {
-      setSessions((current) =>
-        current.filter((session) => session.id !== sessionId),
-      );
+    try {
+      const result = await archiveLighthouseV2Session(sessionId);
+      if ("data" in result) {
+        setSessions((current) =>
+          current.filter((session) => session.id !== sessionId),
+        );
+      }
+    } catch {
+      // Archiving is recoverable from the sidebar; ignore transient failures.
     }
   };
 
diff --git a/ui/app/(prowler)/lighthouse/_lib/messages.ts b/ui/app/(prowler)/lighthouse/_lib/messages.ts
index c23b8242ea..4294660be6 100644
--- a/ui/app/(prowler)/lighthouse/_lib/messages.ts
+++ b/ui/app/(prowler)/lighthouse/_lib/messages.ts
@@ -21,6 +21,10 @@ export function getTextContent(content: unknown): string {
   return "";
 }
 
+// Monotonic counter guaranteeing unique optimistic ids even when two messages
+// are built within the same millisecond (toISOString alone is ms-granular).
+let optimisticMessageCounter = 0;
+
 // Builds a client-only message shown immediately after submit, before the
 // backend echoes the persisted message back through the stream/refresh.
 export function buildOptimisticMessage(
@@ -28,7 +32,8 @@ export function buildOptimisticMessage(
   text: string,
 ): LighthouseV2Message {
   const now = new Date().toISOString();
-  const id = `optimistic-${role}-${now}`;
+  optimisticMessageCounter += 1;
+  const id = `optimistic-${role}-${now}-${optimisticMessageCounter}`;
   return {
     id,
     role,
diff --git a/ui/app/(prowler)/lighthouse/settings/page.tsx b/ui/app/(prowler)/lighthouse/settings/page.tsx
index 2df2e00923..057161bc10 100644
--- a/ui/app/(prowler)/lighthouse/settings/page.tsx
+++ b/ui/app/(prowler)/lighthouse/settings/page.tsx
@@ -1,5 +1,3 @@
-import { Spacer } from "@heroui/spacer";
-
 import {
   getLighthouseV2Configurations,
   getLighthouseV2SupportedProviders,
@@ -45,7 +43,7 @@ export default async function LighthouseSettingsPage() {
   return (
     <ContentLayout title="Settings">
       <LLMProvidersTable />
-      <Spacer y={8} />
+      <div className="h-8" aria-hidden="true" />
       <LighthouseSettings />
     </ContentLayout>
   );
diff --git a/ui/components/lighthouse-v1/ai-elements/conversation.tsx b/ui/components/lighthouse-v1/ai-elements/conversation.tsx
index ec96807893..f1adfa3689 100644
--- a/ui/components/lighthouse-v1/ai-elements/conversation.tsx
+++ b/ui/components/lighthouse-v1/ai-elements/conversation.tsx
@@ -41,7 +41,10 @@ export const ConversationContent = ({
   const { contentRef, scrollRef } = context;
 
   return (
-    <div ref={scrollRef} className={cn("h-full w-full", scrollClassName)}>
+    <div
+      ref={scrollRef}
+      className={cn("h-full min-h-0 w-full overflow-y-auto", scrollClassName)}
+    >
       <div
         ref={contentRef}
         className={cn("flex flex-col gap-8 p-4", className)}
diff --git a/ui/lib/markdown.ts b/ui/lib/markdown.ts
index f45e30e749..88fbb533cb 100644
--- a/ui/lib/markdown.ts
+++ b/ui/lib/markdown.ts
@@ -59,12 +59,15 @@ export function escapeAngleBracketPlaceholders(text: string): string {
         return part;
       }
 
-      // For regular text outside code, wrap placeholders in backticks.
+      // For regular text outside code, escape placeholders as HTML entities so
+      // they render as plain `<bucket_name>` text. Raw HTML parsing is disabled
+      // in both chat renderers, so entities are enough — and avoid the code-span
+      // styling that wrapping in backticks would force.
       return part.replace(/<([a-zA-Z][a-zA-Z0-9_-]*)>/g, (match, tagName) => {
         if (htmlTags.has(tagName.toLowerCase())) {
           return match;
         }
-        return `\`<${tagName}>\``;
+        return `&lt;${tagName}&gt;`;
       });
     })
     .join("");