diff --git a/lib/questionlib.php b/lib/questionlib.php
index b292ee0639256..d07c1de2144cc 100644
--- a/lib/questionlib.php
+++ b/lib/questionlib.php
@@ -1466,6 +1466,13 @@ function question_has_capability_on($questionorid, $cap, $notused = -1): bool {
 
             // Well, at least we tried. Seems that we really have to read from DB.
             $question = $DB->get_record_sql($sql, ['id' => $questionid]);
+
+            // The question does not exist, we return false here to exit
+            // this function and be able to treat it as a missing question
+            // further down the line.
+            if ($question === false) {
+                return false;
+            }
         }
     }
 
diff --git a/lib/tests/questionlib_test.php b/lib/tests/questionlib_test.php
index 7c6cc9c98fcbc..8ce28f10f44b9 100644
--- a/lib/tests/questionlib_test.php
+++ b/lib/tests/questionlib_test.php
@@ -298,6 +298,39 @@ public function test_question_delete_question() {
         $this->assertTrue($DB->record_exists('question', ['id' => $q2->id]));
     }
 
+    /**
+     * Test that a question with a 'draft' status used in a quiz
+     * is hidden instead of deleted.
+     *
+     * @covers ::question_delete_question
+     */
+    public function test_question_delete_question_used_draft() {
+        global $DB;
+        $this->resetAfterTest(true);
+
+        list($category, $course, $quiz, $qcat, $questions) = $this->setup_quiz_and_questions();
+
+        $q1 = $questions[0];
+
+        // Set the status of the question to 'draft'.
+        $DB->set_field(
+            'question_versions',
+            'status',
+            \core_question\local\bank\question_version_status::QUESTION_STATUS_DRAFT,
+            ['questionid' => $q1->id]
+        );
+
+        // Do.
+        question_delete_question($q1->id);
+
+        // Verify that the question is still existing and that the version status is 'hidden'.
+        $this->assertTrue($DB->record_exists('question', ['id' => $q1->id]));
+        $this->assertEquals(
+            $DB->get_record('question_versions', ['questionid' => $q1->id])->status,
+            \core_question\local\bank\question_version_status::QUESTION_STATUS_HIDDEN
+        );
+    }
+
     /**
      * Test that deleting a broken question from the question bank does not cause fatal errors.
      */
diff --git a/mod/quiz/classes/question/bank/qbank_helper.php b/mod/quiz/classes/question/bank/qbank_helper.php
index 2f9c05e18470b..ec8014bb57712 100644
--- a/mod/quiz/classes/question/bank/qbank_helper.php
+++ b/mod/quiz/classes/question/bank/qbank_helper.php
@@ -186,7 +186,7 @@ public static function get_question_structure(int $quizid, \context_module $quiz
                 $slot->length = 1;
             } else if ($slot->qtype === null) {
                 // This question must have gone missing. Put in a placeholder.
-                $slot->questionid = 's' . $slot->id; // Sometimes this is used as an array key, so needs to be unique.
+                $slot->questionid = time() . $slot->id; // Sometimes this is used as an array key, so needs to be unique.
                 $slot->category = 0;
                 $slot->qtype = 'missingtype';
                 $slot->name = get_string('missingquestion', 'quiz');
diff --git a/question/classes/question_reference_manager.php b/question/classes/question_reference_manager.php
index f3bd6c5c1ed37..4fd662a493869 100644
--- a/question/classes/question_reference_manager.php
+++ b/question/classes/question_reference_manager.php
@@ -64,7 +64,6 @@ public static function questions_with_references(array $questionids): array {
                          FROM {question_versions} lqv
                          JOIN {question_versions} lv ON lv.questionbankentryid = lqv.questionbankentryid
                         WHERE lqv.questionid $lqidtest
-                          AND lv.status <> :draft
                      GROUP BY lqv.questionbankentryid
                    ) latestversions ON latestversions.questionbankentryid = qv.questionbankentryid
 
@@ -72,7 +71,7 @@ public static function questions_with_references(array $questionids): array {
                        AND (qr.version = qv.version OR qr.version IS NULL AND qv.version = latestversions.latestusableversion)
 
              WHERE qv.questionid $qidtest
-            ", array_merge($params, $lparams, ['draft' => question_version_status::QUESTION_STATUS_DRAFT]));
+            ", array_merge($params, $lparams));
     }
 
     /**