diff --git a/README.md b/README.md
index abed0b3..fb4922c 100644
--- a/README.md
+++ b/README.md
@@ -103,7 +103,7 @@ Settings can be configured from the sidebar in Claude Code Viewer.
 | Setting | Default | Description |
 | --- | --- | --- |
 | Hide sessions without user messages | true | Claude Code creates logs for operations like `/compact` that aren't tied to actual tasks, which can create noise. When enabled, sessions without user messages are hidden. |
-| Unify sessions with same title | true | When resuming, Claude Code creates a new session with regenerated conversation logs. When enabled, only the latest session with the same title is displayed. |
+| Unify sessions with same title | false | When resuming, Claude Code creates a new session with regenerated conversation logs. When enabled, only the latest session with the same title is displayed. |
 | Enter Key Behavior | Shift+Enter | Specifies which key combination sends messages. Options include Enter, Shift+Enter, and Command+Enter. |
 | Permission Mode | Ask permission | Controls the approval logic when Claude Code requests tool invocations. By default, users approve requests through the UI. This feature requires Claude Code v1.0.82 or later; earlier versions automatically approve regardless of this setting. |
 | Theme | System | Toggles between Dark Mode and Light Mode. Default follows system settings. |
diff --git a/src/server/core/claude-code/services/ClaudeCodeLifeCycleService.ts b/src/server/core/claude-code/services/ClaudeCodeLifeCycleService.ts
index 4097d3f..05b19f1 100644
--- a/src/server/core/claude-code/services/ClaudeCodeLifeCycleService.ts
+++ b/src/server/core/claude-code/services/ClaudeCodeLifeCycleService.ts
@@ -147,8 +147,6 @@ const LayerImpl = Effect.gen(function* () {
 
       const handleMessage = (message: SDKMessage) =>
         Effect.gen(function* () {
-          console.log("[debug] handleMessage", message.type);
-
           const processState = yield* sessionProcessService.getSessionProcess(
             sessionProcess.def.sessionProcessId,
           );
@@ -288,10 +286,6 @@ const LayerImpl = Effect.gen(function* () {
           for await (const message of messageIter) {
             const fallbackMessage = fallbackSdkMessage(message);
 
-            if (fallbackMessage === null) {
-              continue;
-            }
-
             const result = await Runtime.runPromise(runtime)(
               handleMessage(fallbackMessage),
             ).catch((error) => {
diff --git a/src/server/core/platform/services/UserConfigService.ts b/src/server/core/platform/services/UserConfigService.ts
index 6f6734e..a63cf4b 100644
--- a/src/server/core/platform/services/UserConfigService.ts
+++ b/src/server/core/platform/services/UserConfigService.ts
@@ -5,7 +5,7 @@ import type { InferEffect } from "../../../lib/effect/types";
 const LayerImpl = Effect.gen(function* () {
   const configRef = yield* Ref.make<UserConfig>({
     hideNoUserMessageSession: true,
-    unifySameTitleSession: true,
+    unifySameTitleSession: false,
     enterKeyBehavior: "shift-enter-send",
     permissionMode: "default",
     locale: "ja",
diff --git a/src/server/lib/config/config.ts b/src/server/lib/config/config.ts
index 3a6996e..3517798 100644
--- a/src/server/lib/config/config.ts
+++ b/src/server/lib/config/config.ts
@@ -3,7 +3,7 @@ import { localeSchema } from "../../../lib/i18n/schema";
 
 export const userConfigSchema = z.object({
   hideNoUserMessageSession: z.boolean().optional().default(true),
-  unifySameTitleSession: z.boolean().optional().default(true),
+  unifySameTitleSession: z.boolean().optional().default(false),
   enterKeyBehavior: z
     .enum(["shift-enter-send", "enter-send", "command-enter-send"])
     .optional()