Now use empty string for invariant in published

src/Umbraco.Core/Models/PublishedContent/ThreadCultureCurrentVariationAccessor.cs

@@ -16,8 +16,8 @@ namespace Umbraco.Core.Models.PublishedContent
 
         public CurrentVariation CurrentVariation
         {
-            get => _contexts.GetOrAdd(Thread.CurrentThread.CurrentUICulture.Name, culture => new CurrentVariation { Culture = culture });
+            get => _contexts.GetOrAdd(Thread.CurrentThread.CurrentUICulture.Name, culture => new CurrentVariation(culture));
             set => throw new NotSupportedException();
         }
     }
-}
+}