diff --git a/crates/rspack_core/src/compiler/mod.rs b/crates/rspack_core/src/compiler/mod.rs
index 7bc43df7914..c593bee3ab3 100644
--- a/crates/rspack_core/src/compiler/mod.rs
+++ b/crates/rspack_core/src/compiler/mod.rs
@@ -208,7 +208,7 @@ impl Compiler {
       .await
       .err()
     {
-      self.compilation.extend_diagnostics(vec![e.into()]);
+      self.compilation.push_diagnostic(e.into());
     }
     logger.time_end(make_hook_start);
     self.compilation.make().await?;
diff --git a/crates/rspack_core/src/old_cache/occasion/chunk_render.rs b/crates/rspack_core/src/old_cache/occasion/chunk_render.rs
index 81803c7c96a..bda2f35f7a4 100644
--- a/crates/rspack_core/src/old_cache/occasion/chunk_render.rs
+++ b/crates/rspack_core/src/old_cache/occasion/chunk_render.rs
@@ -5,7 +5,7 @@ use rspack_sources::BoxSource;
 
 use crate::{old_cache::storage, Chunk, Compilation, SourceType};
 
-type Storage = dyn storage::Storage<(BoxSource, Vec<Diagnostic>)>;
+type Storage = dyn storage::Storage<BoxSource>;
 
 #[derive(Debug)]
 pub struct ChunkRenderOccasion {
@@ -41,10 +41,10 @@ impl ChunkRenderOccasion {
     };
     let cache_key = Identifier::from(content_hash.encoded());
     if let Some(value) = storage.get(&cache_key) {
-      Ok(value)
+      Ok((value, Vec::new()))
     } else {
       let res = generator().await?;
-      storage.set(cache_key, res.clone());
+      storage.set(cache_key, res.0.clone());
       Ok(res)
     }
   }
diff --git a/crates/rspack_plugin_copy/src/lib.rs b/crates/rspack_plugin_copy/src/lib.rs
index 45a08dffe3f..946357ad77d 100644
--- a/crates/rspack_plugin_copy/src/lib.rs
+++ b/crates/rspack_plugin_copy/src/lib.rs
@@ -275,11 +275,10 @@ impl CopyRspackPlugin {
       }
       Err(e) => {
         let e: Error = DiagnosticError::from(e.boxed()).into();
-        let rspack_err: Vec<Diagnostic> = vec![e.into()];
         diagnostics
           .lock()
           .expect("failed to obtain lock of `diagnostics`")
-          .extend(rspack_err);
+          .push(e.into());
         return None;
       }
     };
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/a.css b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/a.css
new file mode 100644
index 00000000000..f86454b2aea
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/a.css
@@ -0,0 +1,3 @@
+body {
+  content: "a";
+}
\ No newline at end of file
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/ab.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/ab.js
new file mode 100644
index 00000000000..7202aa2ed72
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/ab.js
@@ -0,0 +1,2 @@
+import "./a.css"
+import "./b.css"
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/b.css b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/b.css
new file mode 100644
index 00000000000..be45967cd87
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/b.css
@@ -0,0 +1,3 @@
+body {
+  content: "b";
+}
\ No newline at end of file
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/ba.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/ba.js
new file mode 100644
index 00000000000..413e4d70a36
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/ba.js
@@ -0,0 +1,2 @@
+import "./b.css"
+import "./a.css"
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/warnings.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/warnings.js
new file mode 100644
index 00000000000..9ee3c298cc8
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/0/warnings.js
@@ -0,0 +1,3 @@
+module.exports = [
+  /Conflicting order\. Following module has been added/,
+]
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/1/ab.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/1/ab.js
new file mode 100644
index 00000000000..ae4f710b389
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/1/ab.js
@@ -0,0 +1,2 @@
+// import "./a.css"
+import "./b.css"
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/1/warnings.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/1/warnings.js
new file mode 100644
index 00000000000..d7faf17f9b9
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/1/warnings.js
@@ -0,0 +1 @@
+module.exports = []
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/2/ab.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/2/ab.js
new file mode 100644
index 00000000000..7202aa2ed72
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/2/ab.js
@@ -0,0 +1,2 @@
+import "./a.css"
+import "./b.css"
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/rspack.config.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/rspack.config.js
new file mode 100644
index 00000000000..b91d0068903
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/rspack.config.js
@@ -0,0 +1,42 @@
+const rspack = require("@rspack/core");
+
+/** @type {import("@rspack/core").Configuration} */
+module.exports = {
+  entry: {
+    ab: './ab.js',
+    ba: './ba.js',
+  },
+  output: {
+    filename: '[name].js'
+  },
+  optimization: {
+    splitChunks: {
+      cacheGroups: {
+        styles: {
+          name: "styles",
+          chunks: "all",
+          test: /\.css$/,
+          enforce: true,
+        },
+      },
+    },
+  },
+  plugins: [
+    new rspack.CssExtractRspackPlugin({ ignoreOrder: false }),
+  ],
+  module: {
+    rules: [
+      {
+        test: /\.css$/,
+        use: [
+          rspack.CssExtractRspackPlugin.loader,
+          "css-loader",
+        ],
+        type: "javascript/auto",
+      },
+    ],
+  },
+  experiments: {
+    css: false,
+  },
+};
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/test.config.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/test.config.js
new file mode 100644
index 00000000000..69fd10d0785
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-css-extract/test.config.js
@@ -0,0 +1,5 @@
+module.exports = {
+	findBundle(i) {
+		return ["ab.js", "ba.js"];
+	},
+}
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/a.css b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/a.css
new file mode 100644
index 00000000000..f86454b2aea
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/a.css
@@ -0,0 +1,3 @@
+body {
+  content: "a";
+}
\ No newline at end of file
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/ab.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/ab.js
new file mode 100644
index 00000000000..7202aa2ed72
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/ab.js
@@ -0,0 +1,2 @@
+import "./a.css"
+import "./b.css"
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/b.css b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/b.css
new file mode 100644
index 00000000000..be45967cd87
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/b.css
@@ -0,0 +1,3 @@
+body {
+  content: "b";
+}
\ No newline at end of file
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/ba.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/ba.js
new file mode 100644
index 00000000000..413e4d70a36
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/ba.js
@@ -0,0 +1,2 @@
+import "./b.css"
+import "./a.css"
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/warnings.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/warnings.js
new file mode 100644
index 00000000000..586493b1b50
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/0/warnings.js
@@ -0,0 +1,3 @@
+module.exports = [
+  /Conflicting order between/,
+]
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/1/ab.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/1/ab.js
new file mode 100644
index 00000000000..ae4f710b389
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/1/ab.js
@@ -0,0 +1,2 @@
+// import "./a.css"
+import "./b.css"
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/1/warnings.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/1/warnings.js
new file mode 100644
index 00000000000..d7faf17f9b9
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/1/warnings.js
@@ -0,0 +1 @@
+module.exports = []
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/2/ab.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/2/ab.js
new file mode 100644
index 00000000000..7202aa2ed72
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/2/ab.js
@@ -0,0 +1,2 @@
+import "./a.css"
+import "./b.css"
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/rspack.config.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/rspack.config.js
new file mode 100644
index 00000000000..2f8c9f49d0b
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/rspack.config.js
@@ -0,0 +1,28 @@
+const rspack = require("@rspack/core");
+
+/** @type {import("@rspack/core").Configuration} */
+module.exports = {
+  entry: {
+    ab: './ab.js',
+    ba: './ba.js',
+  },
+  output: {
+    filename: '[name].js'
+  },
+  target: "web",
+  optimization: {
+    splitChunks: {
+      cacheGroups: {
+        styles: {
+          name: "styles",
+          chunks: "all",
+          test: /\.css$/,
+          enforce: true,
+        },
+      },
+    },
+  },
+  experiments: {
+    css: true,
+  },
+};
diff --git a/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/test.config.js b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/test.config.js
new file mode 100644
index 00000000000..69fd10d0785
--- /dev/null
+++ b/packages/rspack-test-tools/tests/watchCases/css/chunk-render-cache-experiments-css/test.config.js
@@ -0,0 +1,5 @@
+module.exports = {
+	findBundle(i) {
+		return ["ab.js", "ba.js"];
+	},
+}