naive solution

src/Illuminate/Database/Concerns/ManagesTransactions.php

@@ -117,9 +117,10 @@ public function beginTransaction()
         $this->createTransaction();
 
         $this->transactions++;
+        $this->uniqueTransactionsCounter++;
 
         $this->transactionsManager?->begin(
-            $this->getName(), $this->transactions
+            $this->getName(), $this->transactions, $this->uniqueTransactionsCounter
         );
 
         $this->fireConnectionEvent('beganTransaction');
@@ -271,7 +272,7 @@ public function rollBack($toLevel = null)
         $this->transactions = $toLevel;
 
         $this->transactionsManager?->rollback(
-            $this->getName(), $this->transactions
+            $this->getName(), $this->transactions, $this->uniqueTransactionsCounter
         );
 
         $this->fireConnectionEvent('rollingBack');

src/Illuminate/Database/Connection.php

@@ -126,6 +126,13 @@ class Connection implements ConnectionInterface
      */
     protected $transactions = 0;
 
+    /**
+     * The global counter for the unique number of transactions.
+     *
+     * @var int
+     */
+    protected $uniqueTransactionsCounter = 0;
+
     /**
      * The transaction manager instance.
      *

src/Illuminate/Database/DatabaseTransactionRecord.php

@@ -18,6 +18,13 @@ class DatabaseTransactionRecord
      */
     public $level;
 
+    /**
+     * The transaction counter.
+     *
+     * @var int
+     */
+    public $counter;
+
     /**
      * The callbacks that should be executed after committing.
      *
@@ -30,12 +37,14 @@ class DatabaseTransactionRecord
      *
      * @param  string  $connection
      * @param  int  $level
+     * @param  int  $counter
      * @return void
      */
-    public function __construct($connection, $level)
+    public function __construct($connection, $level, $counter)
     {
         $this->connection = $connection;
         $this->level = $level;
+        $this->counter = $counter;
     }
 
     /**

src/Illuminate/Database/DatabaseTransactionsManager.php

@@ -26,12 +26,13 @@ public function __construct()
      *
      * @param  string  $connection
      * @param  int  $level
+     * @param  int  $counter
      * @return void
      */
-    public function begin($connection, $level)
+    public function begin($connection, $level, $counter)
     {
         $this->transactions->push(
-            new DatabaseTransactionRecord($connection, $level)
+            new DatabaseTransactionRecord($connection, $level, $counter)
         );
     }
 
@@ -40,12 +41,13 @@ public function begin($connection, $level)
      *
      * @param  string  $connection
      * @param  int  $level
+     * @param  int $counter
      * @return void
      */
-    public function rollback($connection, $level)
+    public function rollback($connection, $level, $counter)
     {
         $this->transactions = $this->transactions->reject(
-            fn ($transaction) => $transaction->connection == $connection && $transaction->level > $level
+            fn ($transaction) => $transaction->connection == $connection && $transaction->level > $level && $transaction->counter === $counter
         )->values();
     }
 

tests/Integration/Database/DatabaseTransactionsTest.php

@@ -14,6 +14,9 @@ public function testTransactionCallbacksDoNotInterfereWithOneAnother()
             new TestObjectForTransactions(),
         ];
 
+        // The problem here is that we're initiating a base transaction, and then two nested transactions.
+        // Although these two nested transactions are not the same, they share the same level (2).
+        // Since they are not the same, the latter one failing should not affect the first one.
         DB::transaction(function () use ($thirdObject, $secondObject, $firstObject) { // Adds a transaction @ level 1
             DB::transaction(function () use ($firstObject) { // Adds a transaction @ level 2
                 DB::afterCommit(fn () => $firstObject->handle()); // Adds a callback to be executed after transaction level 2 is committed