diff --git a/src/PhpSpreadsheet/Cell/DataValidation.php b/src/PhpSpreadsheet/Cell/DataValidation.php
index 79d70a98..7ee53eae 100644
--- a/src/PhpSpreadsheet/Cell/DataValidation.php
+++ b/src/PhpSpreadsheet/Cell/DataValidation.php
@@ -460,6 +460,7 @@ class DataValidation
             $this->error .
             $this->promptTitle .
             $this->prompt .
+            $this->sqref .
             __CLASS__
         );
     }
diff --git a/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php b/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
index 466e8b00..286ebe7e 100644
--- a/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
+++ b/src/PhpSpreadsheet/Writer/Xlsx/Worksheet.php
@@ -85,6 +85,9 @@ class Worksheet extends WriterPart
         // conditionalFormatting
         $this->writeConditionalFormatting($objWriter, $worksheet);
 
+        // dataValidations
+        $this->writeDataValidations($objWriter, $worksheet);
+
         // hyperlinks
         $this->writeHyperlinks($objWriter, $worksheet);
 
@@ -118,8 +121,6 @@ class Worksheet extends WriterPart
         // ConditionalFormattingRuleExtensionList
         // (Must be inserted last. Not insert last, an Excel parse error will occur)
         $this->writeExtLst($objWriter, $worksheet);
-        // dataValidations
-        $this->writeDataValidations($objWriter, $worksheet);
 
         $objWriter->endElement();
 
@@ -681,16 +682,11 @@ class Worksheet extends WriterPart
         // Write data validations?
         if (!empty($dataValidationCollection)) {
             $dataValidationCollection = Coordinate::mergeRangesInCollection($dataValidationCollection);
-            $objWriter->startElement('extLst');
-            $objWriter->startElement('ext');
-            $objWriter->writeAttribute('uri', '{CCE6A557-97BC-4b89-ADB6-D9C93CAAB3DF}');
-            $objWriter->writeAttribute('xmlns:x14', 'http://schemas.microsoft.com/office/spreadsheetml/2009/9/main');
-            $objWriter->startElement('x14:dataValidations');
+            $objWriter->startElement('dataValidations');
             $objWriter->writeAttribute('count', count($dataValidationCollection));
-            $objWriter->writeAttribute('xmlns:xm', 'http://schemas.microsoft.com/office/excel/2006/main');
 
             foreach ($dataValidationCollection as $coordinate => $dv) {
-                $objWriter->startElement('x14:dataValidation');
+                $objWriter->startElement('dataValidation');
 
                 if ($dv->getType() != '') {
                     $objWriter->writeAttribute('type', $dv->getType());
@@ -705,7 +701,6 @@ class Worksheet extends WriterPart
                 }
 
                 $objWriter->writeAttribute('allowBlank', ($dv->getAllowBlank() ? '1' : '0'));
-                // showDropDown is really hideDropDown Excel renders as true = hide, false = show
                 $objWriter->writeAttribute('showDropDown', (!$dv->getShowDropDown() ? '1' : '0'));
                 $objWriter->writeAttribute('showInputMessage', ($dv->getShowInputMessage() ? '1' : '0'));
                 $objWriter->writeAttribute('showErrorMessage', ($dv->getShowErrorMessage() ? '1' : '0'));
@@ -723,24 +718,19 @@ class Worksheet extends WriterPart
                     $objWriter->writeAttribute('prompt', $dv->getPrompt());
                 }
 
+                $objWriter->writeAttribute('sqref', $dv->getSqref() ?? $coordinate);
+
                 if ($dv->getFormula1() !== '') {
-                    $objWriter->startElement('x14:formula1');
-                    $objWriter->writeElement('xm:f', $dv->getFormula1());
-                    $objWriter->endElement();
+                    $objWriter->writeElement('formula1', $dv->getFormula1());
                 }
                 if ($dv->getFormula2() !== '') {
-                    $objWriter->startElement('x14:formula2');
-                    $objWriter->writeElement('xm:f', $dv->getFormula2());
-                    $objWriter->endElement();
+                    $objWriter->writeElement('formula2', $dv->getFormula2());
                 }
-                $objWriter->writeElement('xm:sqref', $dv->getSqref() ?? $coordinate);
 
                 $objWriter->endElement();
             }
 
-            $objWriter->endElement(); // dataValidations
-            $objWriter->endElement(); // ext
-            $objWriter->endElement(); // extLst
+            $objWriter->endElement();
         }
     }
 
diff --git a/tests/PhpSpreadsheetTests/Writer/Xlsx/Issue2368Test.php b/tests/PhpSpreadsheetTests/Writer/Xlsx/Issue2368Test.php
new file mode 100644
index 00000000..8915f5df
--- /dev/null
+++ b/tests/PhpSpreadsheetTests/Writer/Xlsx/Issue2368Test.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Writer\Xlsx;
+
+use PhpOffice\PhpSpreadsheet\Cell\DataValidation;
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx as Writer;
+use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
+
+class Issue2368Test extends AbstractFunctional
+{
+    public function testBoolWrite(): void
+    {
+        // DataValidations were incorrectly written twice.
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $validation = $sheet->getDataValidation('A1:A10');
+        $validation->setType(DataValidation::TYPE_LIST);
+        $validation->setShowDropDown(true);
+        $validation->setFormula1('"Option 1, Option 2"');
+
+        $outputFilename = File::temporaryFilename();
+        $writer = new Writer($spreadsheet);
+        $writer->save($outputFilename);
+        $zipfile = "zip://$outputFilename#xl/worksheets/sheet1.xml";
+        $contents = file_get_contents($zipfile);
+        unlink($outputFilename);
+        $spreadsheet->disconnectWorksheets();
+        if ($contents === false) {
+            self::fail('Unable to open file');
+        } else {
+            self::assertSame(0, substr_count($contents, '<extLst>'));
+            self::assertSame(2, substr_count($contents, 'dataValidations')); // start and end tags
+        }
+    }
+
+    public function testMultipleRange(): void
+    {
+        // DataValidations which were identical except for sqref were incorrectly merged.
+        $filename = 'tests/data/Writer/XLSX/issue.2368new.xlsx';
+        $reader = IOFactory::createReader('Xlsx');
+        $spreadsheet = $reader->load($filename);
+        $sheet = $spreadsheet->getActiveSheet();
+        $validations = $sheet->getDataValidationCollection();
+        /** @var string[] */
+        $ranges = [];
+        foreach ($validations as $validation) {
+            $ranges[] = $validation->getSqref();
+        }
+        self::assertContains('A1:A5', $ranges);
+        self::assertContains('A10:A14', $ranges);
+        self::assertContains('A20:A24', $ranges);
+        self::assertSame('"yes,no"', $sheet->getCell('A3')->getDataValidation()->getFormula1());
+        self::assertSame('"yes,no"', $sheet->getCell('A10')->getDataValidation()->getFormula1());
+        self::assertSame('"yes,no"', $sheet->getCell('A24')->getDataValidation()->getFormula1());
+
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx');
+        $spreadsheet->disconnectWorksheets();
+
+        $sheet2 = $reloadedSpreadsheet->getActiveSheet();
+        $validation2 = $sheet2->getDataValidationCollection();
+        /** @var string[] */
+        $range2 = [];
+        foreach ($validation2 as $validation) {
+            $range2[] = $validation->getSqref();
+        }
+        self::assertContains('A1:A5', $range2);
+        self::assertContains('A10:A14', $range2);
+        self::assertContains('A20:A24', $range2);
+        self::assertSame('"yes,no"', $sheet2->getCell('A3')->getDataValidation()->getFormula1());
+        self::assertSame('"yes,no"', $sheet2->getCell('A10')->getDataValidation()->getFormula1());
+        self::assertSame('"yes,no"', $sheet2->getCell('A24')->getDataValidation()->getFormula1());
+
+        $reloadedSpreadsheet->disconnectWorksheets();
+    }
+}
diff --git a/tests/data/Writer/XLSX/issue.2368new.xlsx b/tests/data/Writer/XLSX/issue.2368new.xlsx
new file mode 100644
index 00000000..dbd693f6
Binary files /dev/null and b/tests/data/Writer/XLSX/issue.2368new.xlsx differ