diff --git a/Classes/Domain/Search/ResultSet/Facets/UrlFacetContainer.php b/Classes/Domain/Search/ResultSet/Facets/UrlFacetContainer.php
index 250624369..349fb319e 100644
--- a/Classes/Domain/Search/ResultSet/Facets/UrlFacetContainer.php
+++ b/Classes/Domain/Search/ResultSet/Facets/UrlFacetContainer.php
@@ -189,7 +189,7 @@ public function getActiveFacetValuesByName(string $facetName): array
             $activeFacets = array_keys($activeFacets);
         }
         array_map(function($activeFacet) use (&$values, $facetName) {
-            $parts = explode(':', $activeFacet, 2);
+            $parts = explode(':', (string)$activeFacet, 2);
             if ($parts[0] === $facetName) {
                 $values[] = $parts[1];
             }
@@ -325,7 +325,7 @@ public function removeAllFacetValuesByName(string $facetName): UrlFacetContainer
         }
 
         $facetValues = array_filter($facetValues, function($facetNameValue) use ($facetName) {
-            $parts = explode(':', $facetNameValue, 2);
+            $parts = explode(':', (string)$facetNameValue, 2);
             return $parts[0] !== $facetName;
         }, $filterOptions);
 
diff --git a/Classes/Domain/Search/SearchRequest.php b/Classes/Domain/Search/SearchRequest.php
index f23ae2b5e..87c005458 100644
--- a/Classes/Domain/Search/SearchRequest.php
+++ b/Classes/Domain/Search/SearchRequest.php
@@ -554,15 +554,14 @@ public function getRawUserQuery()
 
     /**
      * Method to check if the query string is an empty string
-     * (also empty string or whitespaces only are handled as empty).
+     * (also whitespaces only are handled as empty).
      *
      * When no query string is set (null) the method returns false.
      * @return bool
      */
     public function getRawUserQueryIsEmptyString()
     {
-        $path = $this->prefixWithNamespace('q');
-        $query = $this->argumentsAccessor->get($path, null);
+        $query = $this->getRawUserQuery();
 
         if ($query === null) {
             return false;
diff --git a/Classes/Query/Modifier/Faceting.php b/Classes/Query/Modifier/Faceting.php
index 07b58631e..2cd5ff8e9 100644
--- a/Classes/Query/Modifier/Faceting.php
+++ b/Classes/Query/Modifier/Faceting.php
@@ -225,6 +225,16 @@ protected function getFilterParts(array $facetConfiguration, string $facetName,
      */
     protected function getFiltersByFacetName(array $resultParameters, array $allFacets): array
     {
+        // validate $resultParameters['filter'] to be an array of string
+        if (!is_array($resultParameters['filter'])) {
+            return [];
+        }
+        foreach ($resultParameters['filter'] as $filter) {
+            if (!is_string($filter)) {
+                return [];
+            }
+        }
+
         // format for filter URL parameter:
         // tx_solr[filter]=$facetName0:$facetValue0,$facetName1:$facetValue1,$facetName2:$facetValue2
         $filters = array_map('rawurldecode', $resultParameters['filter']);