.NET Core 3预览数据在多个.includes上为空错误

Question

我有一个简单的查询，如下所示：

return await _context.Blog
.Include(x => x.Posts)
.Include(x => x.People)
.ToListAsync();`

运行此命令时，将引发“数据为空”错误。堆栈跟踪开始如下：

at System.Data.SqlTypes.SqlGuid.get_Value()
at Microsoft.Data.SqlClient.SqlDataReader.GetGuid(Int32 i)
at Microsoft.EntityFrameworkCore.Relational.Query.Pipeline.RelationalShapedQueryCompilingExpressionVisitor.IncludeCompilingExpressionVisitor.IncludeCollection[ 
   TEntity,TIncludedEntity](QueryContext queryContext, DbDataReader dbDataReader, 
    TEntity entity, Func`3 outerKeySelector, Func`3 innerKeySelector, Func`4 
   innerShaper, INavigation navigation, INavigation inverseNavigation, 
   Action 2 
    fixup, Boolean trackingQuery, ResultCoordinator resultCoordinator)

如果删除.includes之一，则查询运行正常。我可以删除任何一个，并且查询有效，因此它似乎与一个特定实体无关。我的dbcontext具有如下定义的关系：

entity.HasOne(e => e.Blog)
.WithMany(b => b.Postenter code heres)
.HasForeignKey(r => r.BlogsID)
.HasConstraintName("FK_Post_Blog");

预览版本是否存在某种类型的错误？