diff --git a/docs/architecture/stalker-portal.md b/docs/architecture/stalker-portal.md
index 876581b61..73ea51867 100644
--- a/docs/architecture/stalker-portal.md
+++ b/docs/architecture/stalker-portal.md
@@ -269,12 +269,15 @@ The handshake's `not_valid` flag is propagated into the follow-up
 `get_profile` as `not_valid_token`.
 
 Reuse is gated on a session fingerprint (`stalkerSessionFingerprint`) covering
-the **portal origin, the device identity and the account credentials**, stored
+the **portal endpoint (origin AND path), the device identity and the account
+credentials**, stored
 next to the token as `Playlist.stalkerSessionIdentity` and used for the
 in-run cache as well, so an edit applies without a restart. All three halves
 are load-bearing: `ensureToken()` re-presents tokens in a handshake, so an
 endpoint edit would otherwise disclose the previous portal's bearer token to
-another host; an identity edit must not inherit the old session; and for a
+another portal — and origin alone is not enough, since discovery deliberately
+preserves tenant base paths, so `/tenant-a/…` and `/tenant-b/…` on one host
+are different portals; an identity edit must not inherit the old session; and for a
 status-2 portal the login decides which account the token represents. A token
 with no recorded fingerprint (written before this existed) counts as
 unverified and is never re-presented — such a row owes a full profile anyway,
diff --git a/libs/portal/stalker/data-access/src/lib/stalker-session-store.ts b/libs/portal/stalker/data-access/src/lib/stalker-session-store.ts
index 591cbe1c1..01f311404 100644
--- a/libs/portal/stalker/data-access/src/lib/stalker-session-store.ts
+++ b/libs/portal/stalker/data-access/src/lib/stalker-session-store.ts
@@ -13,8 +13,10 @@ import type { StalkerAuthenticationResult } from './stalker-auth.api';
  * All three halves matter, and each was a real defect when missing:
  *
  * - **Endpoint** — `ensureToken()` re-presents tokens in a handshake, so a
- *   playlist repointed at another host would disclose the previous portal's
- *   bearer token to an unrelated server.
+ *   playlist repointed at another portal would disclose the previous one's
+ *   bearer token to it. Origin alone is not enough: discovery deliberately
+ *   preserves tenant base paths (`/tenant-a/…` vs `/tenant-b/…`), which are
+ *   different portals on one host.
  * - **Identity** — an edited MAC/serial must not inherit the old session.
  * - **Credentials** — for a status-2 portal the login decides which account
  *   the token represents, so changing it must not keep serving the previous
@@ -38,19 +40,31 @@ export function stalkerSessionFingerprint(
     >
 ): string {
     return JSON.stringify([
-        portalOrigin(playlist.portalUrl),
+        portalEndpoint(playlist.portalUrl),
         stalkerIdentityFingerprint(playlist as Playlist),
         playlist.username ?? '',
         playlist.password ?? '',
     ]);
 }
 
-function portalOrigin(portalUrl: string | undefined): string {
+/**
+ * Origin AND path, minus query/fragment — the endpoint a session belongs to.
+ *
+ * No attempt is made to treat different handler paths for the same portal
+ * (`…/portal.php` vs `…/server/load.php`) as equivalent. Both sides of the
+ * comparison read the SAME persisted `portalUrl`, so the same portal always
+ * yields the same key; the value changes only on a real edit or repair, and
+ * both of those re-authenticate anyway. An equivalence rule would add
+ * machinery whose only failure mode is aliasing two genuinely different
+ * endpoints — the exact thing this key exists to prevent.
+ */
+function portalEndpoint(portalUrl: string | undefined): string {
     if (!portalUrl) {
         return '';
     }
     try {
-        return new URL(portalUrl).origin;
+        const parsed = new URL(portalUrl);
+        return `${parsed.origin}${parsed.pathname.replace(/\/+$/, '')}`;
     } catch {
         // Unparseable: fall back to the raw string so a change is still a
         // change — never to a constant, which would alias every endpoint.
diff --git a/libs/portal/stalker/data-access/src/lib/stalker-session.service.spec.ts b/libs/portal/stalker/data-access/src/lib/stalker-session.service.spec.ts
index 523a97f1b..2b2846b64 100644
--- a/libs/portal/stalker/data-access/src/lib/stalker-session.service.spec.ts
+++ b/libs/portal/stalker/data-access/src/lib/stalker-session.service.spec.ts
@@ -985,6 +985,58 @@ describe('StalkerSessionService identity payloads', () => {
         );
     });
 
+    it('refuses a persisted token across tenants on the SAME host', async () => {
+        // Discovery deliberately preserves tenant base paths, so two portals
+        // can share an origin. An origin-only key would send tenant A's
+        // bearer to tenant B.
+        const tenantA = {
+            _id: 'playlist-tenant',
+            portalUrl: 'https://panel.example.com/tenant-a/server/load.php',
+            macAddress,
+            isFullStalkerPortal: true,
+        } as Playlist;
+        playlistsService.getPlaylistById.mockReturnValue(
+            of({
+                ...tenantA,
+                stalkerToken: 'TENANT-A-TOKEN',
+                stalkerSessionIdentity: stalkerSessionFingerprint(tenantA),
+                stalkerWatchdogTimeout: 60,
+            } as Playlist)
+        );
+        const authenticate = jest
+            .spyOn(service, 'authenticate')
+            .mockResolvedValue({ token: 'FRESH', reusedStoredToken: false });
+
+        await service.ensureToken({
+            ...tenantA,
+            portalUrl: 'https://panel.example.com/tenant-b/server/load.php',
+        } as Playlist);
+
+        expect(authenticate).toHaveBeenCalledWith(
+            'https://panel.example.com/tenant-b/server/load.php',
+            macAddress,
+            {},
+            expect.objectContaining({ storedToken: undefined })
+        );
+    });
+
+    it('keeps the session for the same endpoint spelled with a trailing slash', async () => {
+        // Normalisation must not turn a cosmetic difference into a forced
+        // re-authentication.
+        const portal = {
+            _id: 'playlist-slash',
+            portalUrl: 'https://panel.example.com/tenant-a/server/load.php',
+            macAddress,
+            isFullStalkerPortal: true,
+        } as Playlist;
+        expect(
+            stalkerSessionFingerprint({
+                ...portal,
+                portalUrl: 'https://panel.example.com/tenant-a/server/load.php/',
+            } as Playlist)
+        ).toBe(stalkerSessionFingerprint(portal));
+    });
+
     it('refuses a persisted token when the playlist was repointed at another host', async () => {
         // ensureToken re-presents persisted tokens in a handshake, so an
         // identity-only check would disclose the previous portal's bearer