diff --git a/services/lms-service/src/handlers.rs b/services/lms-service/src/handlers.rs
index 04224c5..8078c53 100644
--- a/services/lms-service/src/handlers.rs
+++ b/services/lms-service/src/handlers.rs
@@ -4884,7 +4884,16 @@ pub async fn get_lesson_collaborative_doc(
     .bind(org_ctx.id)
     .fetch_optional(&pool)
     .await
-    .map_err(|_| StatusCode::INTERNAL_SERVER_ERROR)?;
+    .map_err(|e| {
+        tracing::error!(
+            "get_lesson_collaborative_doc: failed to fetch doc for lesson {} org {}: {}",
+            id,
+            org_ctx.id,
+            e
+        );
+        StatusCode::INTERNAL_SERVER_ERROR
+    })
+    .unwrap_or(None);
 
     let doc = row.unwrap_or(DocRow {
         content: String::new(),
@@ -4967,9 +4976,16 @@ pub async fn update_lesson_collaborative_doc(
     if existing.is_none() && payload.base_revision == 0 {
         // Primer guardado
         let course_id = sqlx::query_scalar::<_, Uuid>(
-            "SELECT course_id FROM lessons WHERE id = $1",
+            r#"
+            SELECT m.course_id
+            FROM lessons l
+            JOIN modules m ON m.id = l.module_id
+            JOIN courses c ON c.id = m.course_id
+            WHERE l.id = $1 AND c.organization_id = $2
+            "#,
         )
         .bind(id)
+        .bind(org_ctx.id)
         .fetch_one(&pool)
         .await
         .map_err(|e| (StatusCode::INTERNAL_SERVER_ERROR, e.to_string()))?;
diff --git a/services/lms-service/src/main.rs b/services/lms-service/src/main.rs
index 5703e1e..b8e0a94 100644
--- a/services/lms-service/src/main.rs
+++ b/services/lms-service/src/main.rs
@@ -144,8 +144,10 @@ async fn main() {
     use std::sync::Arc;
 
     let mut governor_conf = GovernorConfigBuilder::default()
-        .const_per_second(10)
-        .const_burst_size(50)
+        // La vista de lecciones abre varias solicitudes concurrentes + 2 streams SSE.
+        // Con límites muy bajos se generan 429 al navegar entre lecciones.
+        .const_per_second(80)
+        .const_burst_size(240)
         .key_extractor(SmartIpKeyExtractor);
 
     let governor_conf = Arc::new(governor_conf.finish().unwrap());
diff --git a/web/experience/src/app/courses/[id]/lessons/[lessonId]/page.tsx b/web/experience/src/app/courses/[id]/lessons/[lessonId]/page.tsx
index 5faca9d..003df07 100644
--- a/web/experience/src/app/courses/[id]/lessons/[lessonId]/page.tsx
+++ b/web/experience/src/app/courses/[id]/lessons/[lessonId]/page.tsx
@@ -44,6 +44,7 @@ export default function LessonPlayerPage({ params }: { params: { id: string, les
     const [allGrades, setAllGrades] = useState<UserGrade[]>([]);
     const [isBookmarked, setIsBookmarked] = useState(false);
     const { user } = useAuth();
+    const userId = user?.id ?? null;
 
     useEffect(() => {
         const fetchAll = async () => {
@@ -55,9 +56,9 @@ export default function LessonPlayerPage({ params }: { params: { id: string, les
                 setLesson(lessonData);
                 setCourse({ ...outlineData.course, modules: outlineData.modules });
 
-                if (user) {
+                if (userId) {
                     const [grades, bookmarks] = await Promise.all([
-                        lmsApi.getUserGrades(user.id, params.id),
+                        lmsApi.getUserGrades(userId, params.id),
                         lmsApi.getBookmarks(params.id)
                     ]);
                     setAllGrades(grades);
@@ -72,7 +73,7 @@ export default function LessonPlayerPage({ params }: { params: { id: string, les
             }
         };
         fetchAll();
-    }, [params.id, params.lessonId, user]);
+    }, [params.id, params.lessonId, userId]);
 
     useEffect(() => {
         if (typeof window === "undefined") return;
diff --git a/web/experience/src/components/CollaborativeDocEditor.tsx b/web/experience/src/components/CollaborativeDocEditor.tsx
index 93d22be..180f1c3 100644
--- a/web/experience/src/components/CollaborativeDocEditor.tsx
+++ b/web/experience/src/components/CollaborativeDocEditor.tsx
@@ -1,7 +1,7 @@
 "use client";
 
 import { useCallback, useEffect, useRef, useState } from "react";
-import { lmsApi, getLmsApiUrl, CollaborativeDoc, UpdateCollaborativeDocResponse } from "@/lib/api";
+import { lmsApi, getLmsApiUrl, getToken, CollaborativeDoc, UpdateCollaborativeDocResponse } from "@/lib/api";
 import {
     AlertTriangle,
     CheckCircle,
@@ -50,11 +50,9 @@ export default function CollaborativeDocEditor({ lessonId }: Props) {
 
     // SSE: escuchar cambios remotos
     useEffect(() => {
-        const token = typeof window !== "undefined"
-            ? localStorage.getItem("lms_token") ?? sessionStorage.getItem("lms_token") ?? ""
-            : "";
+        const token = getToken() || "";
         const baseUrl = getLmsApiUrl();
-        const url = `${baseUrl}/lessons/${lessonId}/collaborative-doc/stream?preview_token=${encodeURIComponent(token)}`;
+        const url = `${baseUrl}/lessons/${lessonId}/collaborative-doc/stream${token ? `?preview_token=${encodeURIComponent(token)}` : ""}`;
 
         const es = new EventSource(url);
         sseRef.current = es;
diff --git a/web/experience/src/components/CollaborativeWhiteboard.tsx b/web/experience/src/components/CollaborativeWhiteboard.tsx
index cb38705..bcc500b 100644
--- a/web/experience/src/components/CollaborativeWhiteboard.tsx
+++ b/web/experience/src/components/CollaborativeWhiteboard.tsx
@@ -1,7 +1,7 @@
 "use client";
 
 import { useCallback, useEffect, useMemo, useRef, useState, type PointerEvent } from "react";
-import { lmsApi, getLmsApiUrl, CollaborativeCanvasState } from "@/lib/api";
+import { lmsApi, getLmsApiUrl, getToken, CollaborativeCanvasState } from "@/lib/api";
 import { AlertTriangle, CheckCircle, Loader2, RefreshCw, Save, Trash2 } from "lucide-react";
 
 type ConflictInfo = {
@@ -61,6 +61,16 @@ export default function CollaborativeWhiteboard({ lessonId }: Props) {
     const [conflict, setConflict] = useState<ConflictInfo | null>(null);
 
     const isDrawing = useRef(false);
+    const dirtyRef = useRef(false);
+    const revisionRef = useRef(0);
+
+    useEffect(() => {
+        dirtyRef.current = dirty;
+    }, [dirty]);
+
+    useEffect(() => {
+        revisionRef.current = revision;
+    }, [revision]);
 
     const allStrokes = useMemo(() => {
         return draftStroke ? [...strokes, draftStroke] : strokes;
@@ -219,24 +229,20 @@ export default function CollaborativeWhiteboard({ lessonId }: Props) {
 
     useEffect(() => {
         const base = getLmsApiUrl();
-        // getToken no es exportada; leemos directamente de sessionStorage/localStorage
-        const token =
-            (typeof window !== "undefined" &&
-                (sessionStorage.getItem("preview_token") || localStorage.getItem("experience_token"))) ||
-            "";
+        const token = getToken() || "";
 
         const url = `${base}/lessons/${lessonId}/collaborative-canvas/stream${token ? `?preview_token=${encodeURIComponent(token)}` : ""}`;
         const es = new EventSource(url);
 
         es.onmessage = (ev) => {
-            if (dirty || isDrawing.current) return;
+            if (dirtyRef.current || isDrawing.current) return;
             try {
                 const data = JSON.parse(ev.data as string) as {
                     revision: number;
                     canvas_state: CollaborativeCanvasState;
                     updated_at: string;
                 };
-                if (data.revision !== revision) {
+                if (data.revision !== revisionRef.current) {
                     setStrokes(toStrokeArray(data.canvas_state || DEFAULT_CANVAS));
                     setRevision(data.revision);
                     setLastSavedAt(data.updated_at);
@@ -253,7 +259,7 @@ export default function CollaborativeWhiteboard({ lessonId }: Props) {
         return () => {
             es.close();
         };
-    }, [dirty, lessonId, revision]);
+    }, [lessonId]);
 
     return (
         <section className="space-y-4 rounded-3xl border border-black/10 dark:border-white/10 bg-white dark:bg-black/20 p-5">
diff --git a/web/experience/src/lib/api.ts b/web/experience/src/lib/api.ts
index 0005301..72962ae 100644
--- a/web/experience/src/lib/api.ts
+++ b/web/experience/src/lib/api.ts
@@ -586,7 +586,7 @@ export interface UpdateAnnouncementPayload {
 
 
 
-const getToken = () => {
+export const getToken = () => {
     if (typeof window === 'undefined') return null;
 
     // Check for preview token in URL