diff --git a/packages/react/src/components/DiffView.tsx b/packages/react/src/components/DiffView.tsx
index 9fbf2be..8cfb89d 100644
--- a/packages/react/src/components/DiffView.tsx
+++ b/packages/react/src/components/DiffView.tsx
@@ -315,22 +315,23 @@ const DiffViewWithRef = <T extends unknown>(
     if (!diffFile) return;
 
     if (props.diffViewHighlight) {
+      // Always call initSyntax when highlight is enabled.
+      // initSyntax() is idempotent — when syntax is already initialized with a
+      // matching highlighter, it efficiently re-syncs syntax line references
+      // from the underlying File objects without recomputing.
+      //
+      // Previously, this effect skipped initSyntax() when the highlighter
+      // name/type already matched. However, on remount the global File cache
+      // causes initRaw() → #syncSyntax() to copy highlighter metadata from
+      // cached File objects into the fresh DiffFile, making it appear that
+      // syntax was already set up when it wasn't. This left syntax lines null
+      // and highlighting was lost on subsequent renders.
       if (registerHighlighter) {
-        if (
-          registerHighlighter.name !== diffFile._getHighlighterName() ||
-          registerHighlighter.type !== diffFile._getHighlighterType() ||
-          registerHighlighter.type !== "class"
-        ) {
-          diffFile.initSyntax({ registerHighlighter: registerHighlighter });
-          diffFile.notifyAll();
-        }
-      } else if (
-        (!diffFile._getIsCloned() && diffFile._getHighlighterName() !== buildInHighlighter.name) ||
-        diffFile._getHighlighterType() !== "class"
-      ) {
+        diffFile.initSyntax({ registerHighlighter: registerHighlighter });
+      } else {
         diffFile.initSyntax();
-        diffFile.notifyAll();
       }
+      diffFile.notifyAll();
     }
   }, [diffFile, props.diffViewHighlight, registerHighlighter, diffViewTheme]);
 
diff --git a/packages/solid/src/components/DiffView.tsx b/packages/solid/src/components/DiffView.tsx
index 00e8cd6..2340071 100644
--- a/packages/solid/src/components/DiffView.tsx
+++ b/packages/solid/src/components/DiffView.tsx
@@ -198,21 +198,11 @@ const InternalDiffView = <T extends unknown>(props: DiffViewProps<T>) => {
       if (props.diffViewHighlight) {
         const registerHighlighter = props.registerHighlighter;
         if (registerHighlighter) {
-          if (
-            registerHighlighter.name !== currentDiffFile._getHighlighterName() ||
-            registerHighlighter.type !== currentDiffFile._getHighlighterType() ||
-            registerHighlighter.type !== "class"
-          ) {
-            currentDiffFile.initSyntax({ registerHighlighter: registerHighlighter });
-            currentDiffFile.notifyAll();
-          }
-        } else if (
-          (!currentDiffFile._getIsCloned() && currentDiffFile._getHighlighterName() !== buildInHighlighter.name) ||
-          currentDiffFile._getHighlighterType() !== "class"
-        ) {
+          currentDiffFile.initSyntax({ registerHighlighter: registerHighlighter });
+        } else {
           currentDiffFile.initSyntax();
-          currentDiffFile.notifyAll();
         }
+        currentDiffFile.notifyAll();
       }
     }
   };
diff --git a/packages/svelte/src/lib/components/DiffView.svelte b/packages/svelte/src/lib/components/DiffView.svelte
index ef055cf..24f5bf9 100644
--- a/packages/svelte/src/lib/components/DiffView.svelte
+++ b/packages/svelte/src/lib/components/DiffView.svelte
@@ -164,23 +164,13 @@
 		if (enableHighlight) {
 			const registerHighlighter = props.registerHighlighter;
 			if (registerHighlighter) {
-				if (
-					registerHighlighter.name !== diffFile._getHighlighterName() ||
-					registerHighlighter.type !== diffFile._getHighlighterType() ||
-					registerHighlighter.type !== 'class'
-				) {
-					diffFile.initSyntax({
-						registerHighlighter: registerHighlighter
-					});
-					diffFile.notifyAll();
-				}
-			} else if (
-				(!diffFile._getIsCloned() && diffFile._getHighlighterName() !== buildInHighlighter.name) ||
-				diffFile._getHighlighterType() !== 'class'
-			) {
+				diffFile.initSyntax({
+					registerHighlighter: registerHighlighter
+				});
+			} else {
 				diffFile.initSyntax();
-				diffFile.notifyAll();
 			}
+			diffFile.notifyAll();
 		}
 	};
 
diff --git a/packages/vue/src/components/DiffView.tsx b/packages/vue/src/components/DiffView.tsx
index df367bd..e287644 100644
--- a/packages/vue/src/components/DiffView.tsx
+++ b/packages/vue/src/components/DiffView.tsx
@@ -165,23 +165,13 @@ export const DiffView = defineComponent<
       if (enableHighlight.value) {
         const registerHighlighter = props.registerHighlighter;
         if (registerHighlighter) {
-          if (
-            registerHighlighter.name !== instance._getHighlighterName() ||
-            registerHighlighter.type !== instance._getHighlighterType() ||
-            registerHighlighter.type !== "class"
-          ) {
-            instance.initSyntax({
-              registerHighlighter: registerHighlighter,
-            });
-            instance.notifyAll();
-          }
-        } else if (
-          (!instance._getIsCloned() && instance._getHighlighterName() !== buildInHighlighter.name) ||
-          instance._getHighlighterType() !== "class"
-        ) {
+          instance.initSyntax({
+            registerHighlighter: registerHighlighter,
+          });
+        } else {
           instance.initSyntax({});
-          instance.notifyAll();
         }
+        instance.notifyAll();
       }
     };