Adapted CombinedConfigDemo with newest Serilog packages to reproduce the problem.

Author: ckadluba

sample/CombinedConfigDemo/CombinedConfigDemo.csproj

@@ -13,6 +13,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.Extensions.Configuration.Json" Version="3.1.4" />
+    <PackageReference Include="Serilog.Sinks.Console" Version="3.1.1" />
   </ItemGroup>
 
   <ItemGroup>

sample/CombinedConfigDemo/Program.cs

@@ -1,5 +1,4 @@
-using System;
-using System.Threading;
+using System.Diagnostics;
 using Microsoft.Extensions.Configuration;
 using Serilog;
 using Serilog.Sinks.MSSqlServer.Sinks.MSSqlServer.Options;
@@ -23,37 +22,35 @@ public static void Main()
             var columnOptionsSection = configuration.GetSection("Serilog:ColumnOptions");
             var sinkOptionsSection = configuration.GetSection("Serilog:SinkOptions");
 
-            // Legacy interace - do not use this anymore
-            //Log.Logger = new LoggerConfiguration()
-            //    .WriteTo.MSSqlServer(
-            //        connectionString: _connectionStringName,
-            //        tableName: _tableName,
-            //        appConfiguration: configuration,
-            //        autoCreateSqlTable: true,
-            //        columnOptionsSection: columnOptionsSection,
-            //        schemaName: _schemaName)
-            //    .CreateLogger();
+            Serilog.Debugging.SelfLog.Enable(m => Debug.WriteLine(m));
 
             // New SinkOptions based interface
-            Log.Logger = new LoggerConfiguration()
+            using (var logger = new LoggerConfiguration()
+                .WriteTo.Console()
                 .WriteTo.MSSqlServer(
                     connectionString: _connectionStringName,
                     sinkOptions: new SinkOptions
                     {
                         TableName = _tableName,
                         SchemaName = _schemaName,
-                        AutoCreateSqlTable = true
+                        AutoCreateSqlTable = false
                     },
                     sinkOptionsSection: sinkOptionsSection,
                     appConfiguration: configuration,
                     columnOptionsSection: columnOptionsSection)
-                .CreateLogger();
-
-            Log.Information("Hello {Name} from thread {ThreadId}", Environment.GetEnvironmentVariable("USERNAME"), Thread.CurrentThread.ManagedThreadId);
-
-            Log.Warning("No coins remain at position {@Position}", new { Lat = 25, Long = 134 });
-
-            Log.CloseAndFlush();
+                .CreateLogger())
+            {
+                logger.Information("Log 1");
+                logger.Information("Log 2");
+                logger.Information("Log 3");
+                logger.Information("Log 4");
+                logger.Information("Log 5");
+                logger.Information("Log 6");
+                logger.Information("Log 7");
+                logger.Information("Log 8");
+                logger.Information("Log 9");
+                logger.Information("Log 10");
+            }
         }
     }
 }

sample/CombinedConfigDemo/appsettings.json

@@ -11,8 +11,7 @@
   },
   "Serilog": {
     "SinkOptions": {
-      "batchPostingLimit": 5,
-      "batchPeriod": "00:00:15"
+      "batchPostingLimit": 500
     },
     "ColumnOptions": {
       "addStandardColumns": [ "LogEvent" ],

src/Serilog.Sinks.MSSqlServer/Serilog.Sinks.MSSqlServer.csproj

@@ -35,8 +35,8 @@
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>
-    <PackageReference Include="Serilog" Version="2.5.0" />
-    <PackageReference Include="Serilog.Sinks.PeriodicBatching" Version="2.1.1" />
+    <PackageReference Include="Serilog" Version="2.9.0" />
+    <PackageReference Include="Serilog.Sinks.PeriodicBatching" Version="2.3.0" />
   </ItemGroup>
 
   <ItemGroup>

src/Serilog.Sinks.MSSqlServer/packages.config

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
   <package id="Serilog" version="2.5.0" targetFramework="net452" />
-  <package id="Serilog.Sinks.PeriodicBatching" version="2.1.1" targetFramework="net452" />
+  <package id="Serilog.Sinks.PeriodicBatching" version="2.3.0" targetFramework="net452" />
   <package id="System.Data.SqlClient" Version="4.6.0" targetFramework="net452" />
 </packages>