diff --git a/packages/survey-core/src/question_matrixdropdownbase.ts b/packages/survey-core/src/question_matrixdropdownbase.ts
index 72b8c7ac95..06c54aa852 100644
--- a/packages/survey-core/src/question_matrixdropdownbase.ts
+++ b/packages/survey-core/src/question_matrixdropdownbase.ts
@@ -1477,6 +1477,7 @@ export class QuestionMatrixDropdownModelBase extends QuestionMatrixBaseModel<Mat
     }
   }
   public runCondition(values: HashTable<any>, properties: HashTable<any>): void {
+    const oldRowVariables = values[MatrixDropdownRowModelBase.RowVariableName];
     super.runCondition(values, properties);
     var counter = 0;
     var prevTotalValue;
@@ -1490,6 +1491,7 @@ export class QuestionMatrixDropdownModelBase extends QuestionMatrixBaseModel<Mat
       counter < 3
     );
     this.updateVisibilityBasedOnRows();
+    values[MatrixDropdownRowModelBase.RowVariableName] = oldRowVariables;
   }
   public runTriggers(name: string, value: any, keys?: any): void {
     super.runTriggers(name, value, keys);
diff --git a/packages/survey-core/tests/question_matrixdynamictests.ts b/packages/survey-core/tests/question_matrixdynamictests.ts
index bf4f4b7d4e..806f4d9420 100644
--- a/packages/survey-core/tests/question_matrixdynamictests.ts
+++ b/packages/survey-core/tests/question_matrixdynamictests.ts
@@ -6669,63 +6669,55 @@ QUnit.test("Detail panel, run conditions", function (assert) {
       },
     ],
   });
-  var matrix = <QuestionMatrixDynamicModel>survey.getQuestionByName("matrix");
-  assert.equal(
-    matrix.detailPanelMode,
-    "underRow",
-    "detail panel mode load correctly"
-  );
-  assert.equal(
-    matrix.detailElements.length,
-    4,
-    "detail elements loads correctly"
-  );
+  const matrix = <QuestionMatrixDynamicModel>survey.getQuestionByName("matrix");
+  assert.equal(matrix.detailPanelMode, "underRow", "detail panel mode load correctly");
+  assert.equal(matrix.detailElements.length, 4, "detail elements loads correctly");
   matrix.visibleRows[0].showDetailPanel();
   assert.ok(matrix.visibleRows[0].detailPanel, "Detail Panel is created");
-  var panel = matrix.visibleRows[0].detailPanel;
-  assert.equal(
-    panel.questions[0].isVisible,
-    false,
-    "first question is invisible"
-  );
-  assert.equal(
-    panel.questions[1].isVisible,
-    false,
-    "second question is invisible"
-  );
-  assert.equal(
-    panel.questions[2].isVisible,
-    false,
-    "third question is invisible"
-  );
-  assert.equal(
-    panel.questions[3].isVisible,
-    true,
-    "fourth question is invisible"
-  );
+  const panel = matrix.visibleRows[0].detailPanel;
+  assert.equal(panel.questions[0].isVisible, false, "first question is invisible");
+  assert.equal(panel.questions[1].isVisible, false, "second question is invisible");
+  assert.equal(panel.questions[2].isVisible, false, "third question is invisible");
+  assert.equal(panel.questions[3].isVisible, true, "fourth question is invisible");
   survey.setValue("question1", "val1");
-  assert.equal(
-    panel.questions[0].isVisible,
-    true,
-    "first question is visible now"
-  );
-  assert.equal(
-    panel.questions[3].isVisible,
-    false,
-    "fourth question is invisible now"
-  );
+  assert.equal(panel.questions[0].isVisible, true, "first question is visible now");
+  assert.equal(panel.questions[3].isVisible, false, "fourth question is invisible now");
   matrix.visibleRows[0].cells[0].question.value = "val2";
-  assert.equal(
-    panel.questions[1].isVisible,
-    true,
-    "second question is visible now"
-  );
+  assert.equal(panel.questions[1].isVisible, true, "second question is visible now");
   panel.getQuestionByName("q2").value = "val3";
-  assert.equal(
-    panel.questions[2].isVisible,
-    true,
-    "third question is visible now"
-  );
+  assert.equal(panel.questions[2].isVisible, true, "third question is visible now");
+});
+QUnit.test("Detail panel, run conditions & matrix before elements, bug#9137", function (assert) {
+  const survey = new SurveyModel({
+    elements: [
+      {
+        type: "matrixdynamic",
+        name: "matrix",
+        rowCount: 2,
+        detailPanelMode: "underRow",
+        columns: [{ name: "col1" }, { name: "col2" }],
+        cellType: "text",
+        detailElements: [
+          { type: "matrixdynamic", name: "m1", columns: [{ name: "col1", defaultValue: "v1" }, { name: "col2", visibleIf: "{row.col1} notempty" }] },
+          { type: "text", name: "q1", visibleIf: "{row.col1} = 'val2'" },
+          { type: "text", name: "q2", visibleIf: "{row.q1} = 'val3'" }
+        ]
+      }
+    ]
+  });
+  const matrix = <QuestionMatrixDynamicModel>survey.getQuestionByName("matrix");
+  matrix.visibleRows[0].showDetailPanel();
+  assert.ok(matrix.visibleRows[0].detailPanel, "Detail Panel is created");
+  const panel = matrix.visibleRows[0].detailPanel;
+  assert.equal(panel.getQuestionByName("m1").visibleRows.length, 2, "nested matrix rows are created");
+  assert.equal(panel.getQuestionByName("q1").isVisible, false, "first question is invisible, #1");
+  assert.equal(panel.getQuestionByName("q2").isVisible, false, "second question is invisible, #1");
+  matrix.visibleRows[0].cells[0].question.value = "val2";
+  assert.equal(panel.getQuestionByName("q1").isVisible, true, "first question is visible, #2");
+  assert.equal(panel.getQuestionByName("q2").isVisible, false, "second question is invisible, #2");
+  panel.getQuestionByName("q1").value = "val3";
+  assert.equal(panel.getQuestionByName("q1").isVisible, true, "first question is visible, #3");
+  assert.equal(panel.getQuestionByName("q2").isVisible, true, "second question is visible, #3");
 });
 QUnit.test("Detail panel and defaultValueFromLastRow", function (assert) {
   var survey = new SurveyModel({