Implement #4678 (Fix #4676) in correct branch

Author: vnbaaij

src/Core/Components/DataGrid/FluentDataGrid.razor.cs

@@ -429,6 +429,7 @@ public partial class FluentDataGrid<TGridItem> : FluentComponentBase, IHandleEve
 
     private GridItemsProvider<TGridItem>? _lastAssignedItemsProvider;
     private CancellationTokenSource? _pendingDataLoadCancellationTokenSource;
+    private bool _isFirstVirtualizeProviderCall = true;
 
     private Exception? _lastError;
     private GridItemsProviderRequest<TGridItem>? _lastRequest;
@@ -889,9 +890,15 @@ private async Task RefreshDataCoreAsync()
         _lastRefreshedPaginationState = Pagination;
 
         // Debounce the requests. This eliminates a lot of redundant queries at the cost of slight lag after interactions.
-        // TODO: Consider making this configurable, or smarter (e.g., doesn't delay on first call in a batch, then the amount
-        // of delay increases if you rapidly issue repeated requests, such as when scrolling a long way)
-        await Task.Delay(100);
+        // Skip the delay on the first call to avoid unnecessary lag on initial load.
+        if (_isFirstVirtualizeProviderCall)
+        {
+            _isFirstVirtualizeProviderCall = false;
+        }
+        else
+        {
+            await Task.Delay(100);
+        }
 
         if (request.CancellationToken.IsCancellationRequested)
         {