diff --git a/web/e2e/tests/secondary-sidebar-isolation.spec.ts b/web/e2e/tests/secondary-sidebar-isolation.spec.ts
new file mode 100644
index 0000000..12dabdd
--- /dev/null
+++ b/web/e2e/tests/secondary-sidebar-isolation.spec.ts
@@ -0,0 +1,77 @@
+import { test, expect } from '@playwright/test';
+import { seedLoreWithFolder, deleteLore, type SeededLore } from '../fixtures/api';
+
+/**
+ * Regression : la secondary sidebar fuyait entre sections.
+ *
+ * Bug initial (2026-05-19) : on est sur /lore/:id (la sidebar affiche l'arbre
+ * du Lore), on clique sur "Campagne" dans la sidebar principale → on arrive
+ * sur /campaigns, MAIS la sidebar secondaire continuait d'afficher l'arbre
+ * du Lore precedent.
+ *
+ * Cause : les composants top-level (campaigns.component, lore.component,
+ * game-systems.component, settings.component) ne nettoyaient pas la sidebar
+ * heritee d'une section precedente. Fix : appel a layoutService.hide() dans
+ * leur ngOnInit.
+ */
+test.describe('Secondary sidebar — isolation entre sections', () => {
+  let seededLore: SeededLore;
+
+  test.beforeEach(async ({ request }) => {
+    seededLore = await seedLoreWithFolder(request);
+  });
+
+  test.afterEach(async ({ request }) => {
+    if (seededLore?.id) await deleteLore(request, seededLore.id);
+  });
+
+  test('Lore detail → /campaigns : la sidebar secondaire disparait', async ({ page }) => {
+    // 1. Sur le detail d'un Lore, la sidebar secondaire est affichee avec
+    //    le nom du Lore comme titre.
+    await page.goto(`/lore/${seededLore.id}`);
+    await expect(page.locator('app-secondary-sidebar')).toBeVisible();
+    await expect(page.locator('app-secondary-sidebar')).toContainText(seededLore.name);
+
+    // 2. Navigation vers la liste des campagnes (top-level).
+    await page.goto('/campaigns');
+    await expect(page.getByRole('heading', { name: /Vos Campagnes/i })).toBeVisible();
+
+    // 3. La sidebar secondaire ne doit PAS persister (sinon elle afficherait
+    //    encore l'arbre du Lore precedent). Le *ngIf au niveau d'AppComponent
+    //    la retire completement du DOM quand layoutService est en etat hidden.
+    await expect(page.locator('app-secondary-sidebar')).toHaveCount(0);
+  });
+
+  test('Lore detail → /game-systems : la sidebar secondaire disparait', async ({ page }) => {
+    await page.goto(`/lore/${seededLore.id}`);
+    await expect(page.locator('app-secondary-sidebar')).toBeVisible();
+
+    await page.goto('/game-systems');
+    await expect(page.getByRole('heading', { name: /Systèmes de JDR/i })).toBeVisible();
+    await expect(page.locator('app-secondary-sidebar')).toHaveCount(0);
+  });
+
+  test('Lore detail → /settings : la sidebar secondaire disparait', async ({ page }) => {
+    await page.goto(`/lore/${seededLore.id}`);
+    await expect(page.locator('app-secondary-sidebar')).toBeVisible();
+
+    await page.goto('/settings');
+    // Settings n'a pas de h1 forcement evident, on se base sur l'URL + l'absence
+    // de sidebar secondaire (objet du test).
+    await expect(page).toHaveURL(/\/settings$/);
+    await expect(page.locator('app-secondary-sidebar')).toHaveCount(0);
+  });
+
+  test('Lore detail → /lore (liste racine) : la sidebar secondaire disparait', async ({ page }) => {
+    // Sur le detail, la sidebar est visible
+    await page.goto(`/lore/${seededLore.id}`);
+    await expect(page.locator('app-secondary-sidebar')).toBeVisible();
+
+    // Retour a la liste racine du Lore
+    await page.goto('/lore');
+    await expect(page.getByRole('heading', { name: /Vos Univers/i })).toBeVisible();
+
+    // La sidebar ne doit plus apparaitre sur la liste racine.
+    await expect(page.locator('app-secondary-sidebar')).toHaveCount(0);
+  });
+});
diff --git a/web/src/app/campaigns/campaigns.component.ts b/web/src/app/campaigns/campaigns.component.ts
index 5017df5..3b8fce2 100644
--- a/web/src/app/campaigns/campaigns.component.ts
+++ b/web/src/app/campaigns/campaigns.component.ts
@@ -3,6 +3,7 @@ import { CommonModule } from '@angular/common';
 import { Router } from '@angular/router';
 import { LucideAngularModule, Map, Plus } from 'lucide-angular';
 import { CampaignService } from '../services/campaign.service';
+import { LayoutService } from '../services/layout.service';
 import { Campaign } from '../services/campaign.model';
 import { CampaignCreateComponent, CampaignCreatePayload } from './campaign/campaign-create/campaign-create.component';
 
@@ -22,10 +23,15 @@ export class CampaignsComponent implements OnInit {
 
   constructor(
     private router: Router,
-    private campaignService: CampaignService
+    private campaignService: CampaignService,
+    private layoutService: LayoutService
   ) {}
 
   ngOnInit(): void {
+    // Liste racine de la section Campagnes : aucune sidebar secondaire ne
+    // doit subsister (ex: si on arrive depuis une page Lore qui en affichait
+    // une, elle persisterait sans ce hide() — cf. bug rapporte 2026-05-19).
+    this.layoutService.hide();
     this.loadCampaigns();
   }
 
diff --git a/web/src/app/game-systems/game-systems.component.ts b/web/src/app/game-systems/game-systems.component.ts
index e2d1d01..42d0bd7 100644
--- a/web/src/app/game-systems/game-systems.component.ts
+++ b/web/src/app/game-systems/game-systems.component.ts
@@ -3,6 +3,7 @@ import { CommonModule } from '@angular/common';
 import { Router } from '@angular/router';
 import { LucideAngularModule, Dices, Plus, Pencil, Trash2 } from 'lucide-angular';
 import { GameSystemService } from '../services/game-system.service';
+import { LayoutService } from '../services/layout.service';
 import { GameSystem } from '../services/game-system.model';
 import { ConfirmDialogService } from '../shared/confirm-dialog/confirm-dialog.service';
 
@@ -24,10 +25,14 @@ export class GameSystemsComponent implements OnInit {
   constructor(
     private router: Router,
     private gameSystemService: GameSystemService,
-    private confirmDialog: ConfirmDialogService
+    private confirmDialog: ConfirmDialogService,
+    private layoutService: LayoutService
   ) {}
 
   ngOnInit(): void {
+    // Page racine : on s'assure de ne pas heriter de la sidebar d'une
+    // section precedente (cf. fix CampaignsComponent / LoreComponent).
+    this.layoutService.hide();
     this.load();
   }
 
diff --git a/web/src/app/lore/lore.component.ts b/web/src/app/lore/lore.component.ts
index 1f227af..7292bd5 100644
--- a/web/src/app/lore/lore.component.ts
+++ b/web/src/app/lore/lore.component.ts
@@ -3,6 +3,7 @@ import { CommonModule } from '@angular/common';
 import { Router } from '@angular/router';
 import { LucideAngularModule, BookOpen, Folder, Plus } from 'lucide-angular';
 import { LoreService } from '../services/lore.service';
+import { LayoutService } from '../services/layout.service';
 import { Lore } from '../services/lore.model';
 import { LoreCreateComponent } from './lore-create/lore-create.component';
 
@@ -26,10 +27,15 @@ export class LoreComponent implements OnInit {
 
   constructor(
     private loreService: LoreService,
+    private layoutService: LayoutService,
     private router: Router
   ) {}
 
   ngOnInit(): void {
+    // Liste racine de la section Lore : aucune sidebar secondaire ne doit
+    // subsister (sinon elle persiste depuis la section precedente — bug
+    // symetrique a celui de CampaignsComponent).
+    this.layoutService.hide();
     this.loadLores();
   }
 
diff --git a/web/src/app/settings/settings.component.ts b/web/src/app/settings/settings.component.ts
index 0d754f0..88207ee 100644
--- a/web/src/app/settings/settings.component.ts
+++ b/web/src/app/settings/settings.component.ts
@@ -7,6 +7,7 @@ import { LucideAngularModule, ArrowLeft, RefreshCw, Save, Check, AlertCircle, Do
 import { SettingsService, AppSettings, AppSettingsUpdate, OneMinModelGroup, OllamaPullEvent } from '../services/settings.service';
 import { UpdatesService, UpdateStatus } from '../services/updates.service';
 import { ConfigService } from '../services/config.service';
+import { LayoutService } from '../services/layout.service';
 import { LicenseService, LicenseStatusDTO, BetaStatusDTO, ChannelStatusDTO, ChannelName } from '../services/license.service';
 import { ConfirmDialogService } from '../shared/confirm-dialog/confirm-dialog.service';
 
@@ -133,10 +134,14 @@ export class SettingsComponent implements OnInit, OnDestroy {
     private updatesService: UpdatesService,
     public config: ConfigService,
     private licenseService: LicenseService,
-    private confirmDialog: ConfirmDialogService
+    private confirmDialog: ConfirmDialogService,
+    private layoutService: LayoutService
   ) {}
 
   ngOnInit(): void {
+    // Page racine : on s'assure de ne pas heriter de la sidebar d'une
+    // section precedente (cf. fix CampaignsComponent / LoreComponent).
+    this.layoutService.hide();
     this.loadSettings();
     if (this.config.updateCheckEnabled) {
       this.checkUpdates();