diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0893d7fb57..83351a04a5 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Removed the deprecated `SymbolProfile` field from the activity interface
+- Refactored the language redirect of the root path from the static file serving configuration to a dedicated middleware
+
+### Fixed
+
+- Fixed the `RangeNotSatisfiableError` for requests with a `Range` header to the root path caused by the empty `index.html` placeholder
+- Fixed the unresolved template literal in the page title while the app is loading from the service worker cache
 
 ## 3.30.0 - 2026-07-19
 
diff --git a/apps/api/src/app/app.module.ts b/apps/api/src/app/app.module.ts
index 4bdd50c9e8..bd76ef49b4 100644
--- a/apps/api/src/app/app.module.ts
+++ b/apps/api/src/app/app.module.ts
@@ -14,8 +14,6 @@ import { DataGatheringQueueModule } from '@ghostfolio/api/services/queues/data-g
 import { PortfolioSnapshotQueueModule } from '@ghostfolio/api/services/queues/portfolio-snapshot/portfolio-snapshot.module';
 import {
   BULL_BOARD_ROUTE,
-  DEFAULT_LANGUAGE_CODE,
-  SUPPORTED_LANGUAGE_CODES,
   THROTTLE_DEFAULT_LIMIT,
   THROTTLE_DEFAULT_TTL
 } from '@ghostfolio/common/config';
@@ -143,29 +141,7 @@ import { UserModule } from './user/user.module';
         '/api/*wildcard',
         '/sitemap.xml'
       ],
-      rootPath: join(__dirname, '..', 'client'),
-      serveStaticOptions: {
-        setHeaders: (res) => {
-          if (res.req?.path === '/') {
-            let languageCode = DEFAULT_LANGUAGE_CODE;
-
-            try {
-              const code = res.req.headers['accept-language']
-                .split(',')[0]
-                .split('-')[0];
-
-              if (
-                (SUPPORTED_LANGUAGE_CODES as readonly string[]).includes(code)
-              ) {
-                languageCode = code;
-              }
-            } catch {}
-
-            res.set('Location', `/${languageCode}`);
-            res.statusCode = StatusCodes.MOVED_PERMANENTLY;
-          }
-        }
-      }
+      rootPath: join(__dirname, '..', 'client')
     }),
     ServeStaticModule.forRoot({
       rootPath: join(__dirname, '..', 'client', '.well-known'),
diff --git a/apps/api/src/main.ts b/apps/api/src/main.ts
index 33ad032e98..77d571ea0b 100644
--- a/apps/api/src/main.ts
+++ b/apps/api/src/main.ts
@@ -1,3 +1,4 @@
+import { languageRedirectMiddleware } from '@ghostfolio/api/middlewares/language-redirect.middleware';
 import { ConfigurationService } from '@ghostfolio/api/services/configuration/configuration.service';
 import {
   BULL_BOARD_ROUTE,
@@ -100,6 +101,8 @@ async function bootstrap() {
     });
   }
 
+  app.use(languageRedirectMiddleware);
+
   const configurationService = app.get(ConfigurationService);
 
   const trustProxy = configurationService.get('TRUST_PROXY');
diff --git a/apps/api/src/middlewares/html-template.middleware.ts b/apps/api/src/middlewares/html-template.middleware.ts
index bdace34024..928a9f22c5 100644
--- a/apps/api/src/middlewares/html-template.middleware.ts
+++ b/apps/api/src/middlewares/html-template.middleware.ts
@@ -111,7 +111,13 @@ export class HtmlTemplateMiddleware implements NestMiddleware {
       );
 
       try {
-        map[languageCode] = readFileSync(indexHtmlPath, 'utf8');
+        // Restore the interpolation token which the template replaces with a
+        // static fallback title to avoid showing an unresolved template
+        // literal when served without interpolation (e.g. by the service worker)
+        map[languageCode] = readFileSync(indexHtmlPath, 'utf8').replace(
+          /<title>.*?<\/title>/,
+          '<title>${title}</title>'
+        );
       } catch {
         this.logger.warn(
           `Skipping language '${languageCode}': ${indexHtmlPath} not found`
diff --git a/apps/api/src/middlewares/language-redirect.middleware.ts b/apps/api/src/middlewares/language-redirect.middleware.ts
new file mode 100644
index 0000000000..5b6fac6c43
--- /dev/null
+++ b/apps/api/src/middlewares/language-redirect.middleware.ts
@@ -0,0 +1,37 @@
+import { environment } from '@ghostfolio/api/environments/environment';
+import {
+  DEFAULT_LANGUAGE_CODE,
+  SUPPORTED_LANGUAGE_CODES
+} from '@ghostfolio/common/config';
+
+import { NextFunction, Request, Response } from 'express';
+import { StatusCodes } from 'http-status-codes';
+
+export function languageRedirectMiddleware(
+  request: Request,
+  response: Response,
+  next: NextFunction
+) {
+  if (
+    !environment.production ||
+    request.path !== '/' ||
+    !['GET', 'HEAD'].includes(request.method)
+  ) {
+    return next();
+  }
+
+  let languageCode = DEFAULT_LANGUAGE_CODE;
+
+  try {
+    const code = request.headers['accept-language'].split(',')[0].split('-')[0];
+
+    if ((SUPPORTED_LANGUAGE_CODES as readonly string[]).includes(code)) {
+      languageCode = code;
+    }
+  } catch {}
+
+  return response.redirect(
+    StatusCodes.MOVED_PERMANENTLY,
+    `/${languageCode}${request.url.slice(1)}`
+  );
+}
diff --git a/apps/client/project.json b/apps/client/project.json
index 9b0e8dafe2..c6367144ee 100644
--- a/apps/client/project.json
+++ b/apps/client/project.json
@@ -203,9 +203,6 @@
           {
             "command": "shx cp apps/client/src/assets/favicon.ico dist/apps/client"
           },
-          {
-            "command": "shx cp apps/client/src/assets/index.html dist/apps/client"
-          },
           {
             "command": "shx cp apps/client/src/assets/robots.txt dist/apps/client"
           },
diff --git a/apps/client/src/app/components/admin-overview/admin-overview.component.ts b/apps/client/src/app/components/admin-overview/admin-overview.component.ts
index 62bc78df16..0bed8111fb 100644
--- a/apps/client/src/app/components/admin-overview/admin-overview.component.ts
+++ b/apps/client/src/app/components/admin-overview/admin-overview.component.ts
@@ -213,9 +213,16 @@ export class GfAdminOverviewComponent implements OnInit {
       duration: this.couponDuration
     };
 
+    const hasCopiedCouponCode = this.clipboard.copy(newCoupon.code);
+
     const coupons = [...this.couponsDataSource.data, newCoupon];
 
-    this.saveCoupons({ coupons, codeToCopy: newCoupon.code });
+    this.saveCoupons({
+      coupons,
+      snackBarMessage: hasCopiedCouponCode
+        ? '✅ ' + $localize`${newCoupon.code} has been copied to the clipboard`
+        : '✅ ' + $localize`Coupon ${newCoupon.code} has been created`
+    });
   }
 
   protected onChangeCouponDuration(aCouponDuration: StringValue) {
@@ -374,11 +381,11 @@ export class GfAdminOverviewComponent implements OnInit {
   }
 
   private saveCoupons({
-    codeToCopy,
-    coupons
+    coupons,
+    snackBarMessage
   }: {
-    codeToCopy?: string;
     coupons: Coupon[];
+    snackBarMessage?: string;
   }) {
     this.dataService
       .putAdminSetting(PROPERTY_COUPONS, {
@@ -388,14 +395,10 @@ export class GfAdminOverviewComponent implements OnInit {
       .subscribe(() => {
         this.couponsDataSource.data = coupons;
 
-        if (codeToCopy) {
-          this.clipboard.copy(codeToCopy);
-
-          this.snackBar.open(
-            '✅ ' + $localize`${codeToCopy} has been copied to the clipboard`,
-            undefined,
-            { duration: ms('3 seconds') }
-          );
+        if (snackBarMessage) {
+          this.snackBar.open(snackBarMessage, undefined, {
+            duration: ms('3 seconds')
+          });
         }
 
         this.changeDetectorRef.markForCheck();
diff --git a/apps/client/src/assets/index.html b/apps/client/src/assets/index.html
deleted file mode 100644
index e69de29bb2..0000000000
diff --git a/apps/client/src/index.html b/apps/client/src/index.html
index c923e3e0c5..61953bca8d 100644
--- a/apps/client/src/index.html
+++ b/apps/client/src/index.html
@@ -1,7 +1,7 @@
 <!doctype html>
 <html class="h-100 position-relative" lang="${languageCode}">
   <head>
-    <title>${title}</title>
+    <title>Ghostfolio</title>
     <base href="/" />
     <meta charset="utf-8" />
     <meta content="yes" name="apple-mobile-web-app-capable" />