diff --git a/app/Http/Controllers/SearchController.php b/app/Http/Controllers/SearchController.php
index b482fa41f..e762fcdd7 100644
--- a/app/Http/Controllers/SearchController.php
+++ b/app/Http/Controllers/SearchController.php
@@ -54,7 +54,7 @@ class SearchController extends BasePageController
         $category = [0];
         $lastvisit = $this->userdata->lastlogin;
 
-        if ($searchType === 'basic' && $request->missing('searchadvr') && ($request->has('id') || $request->has('subject') || $request->has('search'))) {
+        if ($searchType === 'basic' && ($request->filled('id') || $request->filled('subject') || $request->filled('search'))) {
             $searchString = [];
             switch (true) {
                 case $request->filled('subject'):
@@ -73,13 +73,7 @@ class SearchController extends BasePageController
                     $searchString['searchname'] = '';
             }
 
-            $categoryID = [-1];
-            if ($request->has('t')) {
-                $t = $request->input('t');
-                if ($t !== null && $t !== '') {
-                    $categoryID = array_map('intval', explode(',', (string) $t));
-                }
-            }
+            $categoryID = $this->resolveCategoryIdsFromRequest($request);
 
             $orderByUrls = [];
             foreach ($this->releaseBrowseService->getBrowseOrdering() as $orderType) {
@@ -172,12 +166,15 @@ class SearchController extends BasePageController
             }
         }
 
-        if ($searchType !== 'basic' && $request->missing('id') && $request->missing('subject') && $request->anyFilled(['searchadvr', 'searchadvsubject', 'searchadvfilename', 'searchadvposter', 'minage', 'maxage', 'group', 'minsize', 'maxsize', 'search'])) {
+        if ($searchType !== 'basic' && $request->missing('id') && $request->missing('subject') && $request->anyFilled(['searchadvr', 'searchadvsubject', 'searchadvfilename', 'searchadvposter', 'search'])) {
             $orderByString = '';
             foreach ($searchVars as $searchVarKey => $searchVar) {
                 $orderByString .= "&$searchVarKey=".htmlentities($searchVar, ENT_QUOTES | ENT_HTML5);
             }
             $orderByString = ltrim($orderByString, '&');
+            if ($request->filled('t')) {
+                $orderByString .= '&t='.urlencode((string) $request->input('t'));
+            }
 
             $orderByUrls = [];
             foreach ($ordering as $orderType) {
@@ -204,7 +201,7 @@ class SearchController extends BasePageController
                 -1,
                 $this->userdata->categoryexclusions ?? [],
                 'advanced',
-                [$searchVars['searchadvcat'] === '' ? -1 : $searchVars['searchadvcat']]
+                $this->resolveCategoryIdsFromRequest($request)
             );
 
             $results = $this->paginate($rslt ?? [], $rslt[0]->_totalrows ?? 0, config('nntmux.items_per_page'), $page, $request->url(), $request->query());
@@ -236,4 +233,18 @@ class SearchController extends BasePageController
 
         return view('search.index', $this->viewData);
     }
+
+    /**
+     * @return array<int>
+     */
+    private function resolveCategoryIdsFromRequest(Request $request): array
+    {
+        $raw = $request->input('t', $request->input('searchadvcat', ''));
+
+        if ($raw === null || $raw === '' || $raw === '-1') {
+            return [-1];
+        }
+
+        return array_map('intval', explode(',', (string) $raw));
+    }
 }
diff --git a/app/Services/Releases/ReleaseSearchService.php b/app/Services/Releases/ReleaseSearchService.php
index 1da60b1f1..90328ab3f 100644
--- a/app/Services/Releases/ReleaseSearchService.php
+++ b/app/Services/Releases/ReleaseSearchService.php
@@ -75,7 +75,12 @@ class ReleaseSearchService
             return $value !== -1 && $value !== '' && $value !== null;
         });
 
-        if (empty($searchFields)) {
+        if ($searchFields === []) {
+            return collect();
+        }
+
+        $categoryIds = $this->resolveSearchCategoryIds($cat, $excludedCats);
+        if ($categoryIds === []) {
             return collect();
         }
 
@@ -90,18 +95,6 @@ class ReleaseSearchService
                 }
             }
 
-            $categoryIdsRaw = Category::getCategorySearch($cat, null, true);
-
-            $categoryIds = null;
-            if (is_array($categoryIdsRaw)) {
-                $categoryIds = array_values(array_filter(
-                    array_map(static fn ($id): int => (int) $id, $categoryIdsRaw),
-                    static fn (int $id): bool => $id > 0
-                ));
-            } elseif (is_int($categoryIdsRaw) || (is_string($categoryIdsRaw) && ctype_digit((string) $categoryIdsRaw))) {
-                $categoryIds = [(int) $categoryIdsRaw];
-            }
-
             [$sizeMinFromRange, $sizeMaxFromRange] = $this->resolveSizeRangeBounds($sizeFrom, $sizeTo);
             $minSizeCriteria = max((int) $minSize, $sizeMinFromRange);
             $maxSizeCriteria = $sizeMaxFromRange;
@@ -1847,6 +1840,40 @@ class ReleaseSearchService
         return [$minDate, $maxDate];
     }
 
+    /**
+     * Resolve leaf category IDs for search/browse filters (expands root categories).
+     *
+     * @param  array<int|string, mixed>  $cat
+     * @param  array<int|string, mixed>  $excludedCats
+     * @return array<int>|null null = no category filter; [] = filter matches nothing
+     */
+    private function resolveSearchCategoryIds(array $cat, array $excludedCats): ?array
+    {
+        $categoryIdsRaw = Category::getCategorySearch($cat, null, true);
+
+        $categoryIds = null;
+        if (is_array($categoryIdsRaw)) {
+            $categoryIds = array_values(array_filter(
+                array_map(static fn ($id): int => (int) $id, $categoryIdsRaw),
+                static fn (int $id): bool => $id > 0
+            ));
+        } elseif (is_int($categoryIdsRaw) || (is_string($categoryIdsRaw) && ctype_digit((string) $categoryIdsRaw))) {
+            $categoryIds = [(int) $categoryIdsRaw];
+        }
+
+        if (! is_array($categoryIds) || $categoryIds === []) {
+            return $categoryIds;
+        }
+
+        if ($excludedCats === []) {
+            return $categoryIds;
+        }
+
+        $excluded = array_map(static fn ($id): int => (int) $id, $excludedCats);
+
+        return array_values(array_diff($categoryIds, $excluded));
+    }
+
     /**
      * Build category condition for web search (basic and advanced).
      *
diff --git a/resources/views/search/index.blade.php b/resources/views/search/index.blade.php
index c7ef86968..2a56ec060 100644
--- a/resources/views/search/index.blade.php
+++ b/resources/views/search/index.blade.php
@@ -50,6 +50,9 @@
             </div>
 
             <!-- Category -->
+            @php
+                $selectedCategory = request('t', request('searchadvcat', ''));
+            @endphp
             <div>
                 <label for="category" class="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">Category</label>
                 <select id="category"
@@ -63,7 +66,7 @@
                                 $parentTitle = is_object($parentcat) ? $parentcat->title : ($parentcat['title'] ?? 'Category');
                                 $subcategories = is_object($parentcat) ? $parentcat->categories : ($parentcat['categories'] ?? []);
                             @endphp
-                            <option value="{{ $parentId }}" class="font-semibold" {{ request('t') == $parentId ? 'selected' : '' }}>
+                            <option value="{{ $parentId }}" class="font-semibold" {{ (string) $selectedCategory === (string) $parentId ? 'selected' : '' }}>
                                 {{ $parentTitle }}
                             </option>
                             @foreach($subcategories as $subcat)
@@ -71,14 +74,14 @@
                                     $subcatId = is_object($subcat) ? $subcat->id : ($subcat['id'] ?? '');
                                     $subcatTitle = is_object($subcat) ? $subcat->title : ($subcat['title'] ?? '');
                                 @endphp
-                                <option value="{{ $subcatId }}" {{ request('t') == $subcatId ? 'selected' : '' }}>
+                                <option value="{{ $subcatId }}" {{ (string) $selectedCategory === (string) $subcatId ? 'selected' : '' }}>
                                     &nbsp;&nbsp;{{ $subcatTitle }}
                                 </option>
                             @endforeach
                         @endforeach
                     @elseif(isset($catlist))
                         @foreach($catlist as $catId => $catTitle)
-                            <option value="{{ $catId }}" {{ request('t') == $catId ? 'selected' : '' }}>
+                            <option value="{{ $catId }}" {{ (string) $selectedCategory === (string) $catId ? 'selected' : '' }}>
                                 {{ $catTitle }}
                             </option>
                         @endforeach