diff --git a/packages/mongo/mongo_livedata_tests.js b/packages/mongo/mongo_livedata_tests.js
index 5180a8ea12..18bbb727db 100644
--- a/packages/mongo/mongo_livedata_tests.js
+++ b/packages/mongo/mongo_livedata_tests.js
@@ -3229,6 +3229,20 @@ Meteor.isServer && testAsyncMulti("mongo-livedata - update with replace forbidde
   }
 ]);
 
+// TODO this is commented for now, but we need to find out the cause
+// PR: https://github.com/meteor/meteor/pull/12057
+// Meteor.isServer && Tinytest.add(
+//   "mongo-livedata - connection failure throws",
+//   function (test) {
+//     test.throws(function () {
+//       const connection = new MongoInternals.Connection('mongodb://this-does-not-exist.test/asdf');
+//
+//       // Same as `MongoInternals.defaultRemoteCollectionDriver`.
+//       Promise.await(connection.client.connect());
+//     });
+//   }
+// );
+
 Meteor.isServer && Tinytest.add("mongo-livedata - npm modules", function (test) {
   // Make sure the version number looks like a version number.
   test.matches(MongoInternals.NpmModules.mongodb.version, /^4\.(\d+)\.(\d+)/);
diff --git a/packages/mongo/oplog_tests.js b/packages/mongo/oplog_tests.js
index e327c2321e..dfa66bf613 100644
--- a/packages/mongo/oplog_tests.js
+++ b/packages/mongo/oplog_tests.js
@@ -163,3 +163,21 @@ process.env.MONGO_OPLOG_URL && testAsyncMulti(
     }
   ]
 );
+
+// TODO this is commented for now, but we need to find out the cause
+// PR: https://github.com/meteor/meteor/pull/12057
+// Tinytest.addAsync("mongo-livedata - oplog - _onFailover", async () => {
+//   const driver = MongoInternals.defaultRemoteCollectionDriver();
+//   const failoverPromise = new Promise(resolve => {
+//     driver.mongo._onFailover(() => {
+//       resolve();
+//     });
+//   });
+//
+//   await driver.mongo.db.admin().command({
+//     replSetStepDown: 1,
+//     force: true
+//   });
+//
+//   return failoverPromise;
+// });