lock q

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/ToUniTaskAsyncEnumerable.cs

@@ -248,6 +248,8 @@ namespace Cysharp.Threading.Tasks.Linq
                         return current;
                     }
 
+                    lock (queuedResult)
+                    {
                         if (queuedResult.Count != 0)
                         {
                             current = queuedResult.Dequeue();
@@ -260,6 +262,7 @@ namespace Cysharp.Threading.Tasks.Linq
                         }
                     }
                 }
+            }
 
             public UniTask<bool> MoveNextAsync()
             {