diff --git a/packages/front/src/core/PostproductionRenderer/src/simple-outline-pass.ts b/packages/front/src/core/PostproductionRenderer/src/simple-outline-pass.ts
index 07cf2cd9..3d5809a7 100644
--- a/packages/front/src/core/PostproductionRenderer/src/simple-outline-pass.ts
+++ b/packages/front/src/core/PostproductionRenderer/src/simple-outline-pass.ts
@@ -90,7 +90,7 @@ export class SimpleOutlinePass extends Pass {
    * source meshes, their `attributes`, and their `index` belong to
    * fragments and are never mutated here.
    */
-  private _outlinedTiles = new Map<THREE.Mesh, OutlinedTileProxy>();
+  private _outlinedTiles = new Map<string, OutlinedTileProxy>();
   private _nextId = 1;
   private _maxThickness = 2;
 
@@ -327,6 +327,11 @@ export class SimpleOutlinePass extends Pass {
     if (name === DEFAULT_GROUP) return;
     const group = this._groups.get(name);
     if (!group) return;
+    for (const [key, target] of this._outlinedTiles) {
+      if (target.groupName !== name) continue;
+      target.proxy.removeFromParent();
+      this._outlinedTiles.delete(key);
+    }
     while (group.container.children.length) {
       group.container.children[0].removeFromParent();
     }
@@ -385,21 +390,13 @@ export class SimpleOutlinePass extends Pass {
     let group = this._groups.get(groupName);
     if (!group) group = this.addGroup(groupName);
 
-    const existing = this._outlinedTiles.get(tile);
+    const key = this.getOutlinedTileKey(tile, groupName);
+    const existing = this._outlinedTiles.get(key);
     if (existing) {
-      // Reuse the proxy shell; rebuild geometry groups against the new
-      // chunks, and re-home it if the group changed.
       const proxy = existing.proxy;
       const proxyGeom = proxy.geometry;
       proxyGeom.clearGroups();
       this.fillProxyGroups(proxyGeom, chunks);
-      if (existing.groupName !== groupName) {
-        proxy.removeFromParent();
-        // Material must stay as a single-element array; see comment below.
-        proxy.material = [group.material];
-        group.container.add(proxy);
-        existing.groupName = groupName;
-      }
       return;
     }
 
@@ -423,7 +420,7 @@ export class SimpleOutlinePass extends Pass {
     proxy.matrixWorld.copy(tile.matrixWorld);
 
     group.container.add(proxy);
-    this._outlinedTiles.set(tile, { source: tile, proxy, groupName });
+    this._outlinedTiles.set(key, { source: tile, proxy, groupName });
   }
 
   /**
@@ -440,15 +437,31 @@ export class SimpleOutlinePass extends Pass {
    * The proxy's tiny BufferGeometry wrapper (just metadata) is left to
    * GC. Attributes and index belong to fragments.
    */
-  detachOutlinedTile(tile: THREE.Mesh) {
-    const target = this._outlinedTiles.get(tile);
-    if (!target) return;
-    target.proxy.removeFromParent();
-    this._outlinedTiles.delete(tile);
+  detachOutlinedTile(tile: THREE.Mesh, groupName?: string) {
+    if (groupName !== undefined) {
+      const key = this.getOutlinedTileKey(tile, groupName);
+      const target = this._outlinedTiles.get(key);
+      if (!target) return;
+      target.proxy.removeFromParent();
+      this._outlinedTiles.delete(key);
+      return;
+    }
+
+    for (const [key, target] of this._outlinedTiles) {
+      if (target.source !== tile) continue;
+      target.proxy.removeFromParent();
+      this._outlinedTiles.delete(key);
+    }
   }
 
-  hasOutlinedTile(tile: THREE.Mesh) {
-    return this._outlinedTiles.has(tile);
+  hasOutlinedTile(tile: THREE.Mesh, groupName?: string) {
+    if (groupName !== undefined) {
+      return this._outlinedTiles.has(this.getOutlinedTileKey(tile, groupName));
+    }
+    for (const target of this._outlinedTiles.values()) {
+      if (target.source === tile) return true;
+    }
+    return false;
   }
 
   /**
@@ -626,6 +639,10 @@ export class SimpleOutlinePass extends Pass {
     }
   }
 
+  private getOutlinedTileKey(tile: THREE.Mesh, groupName: string) {
+    return `${groupName}:${tile.uuid}`;
+  }
+
   // ---------------------------------------------------------------------------
   // Internals
   // ---------------------------------------------------------------------------
diff --git a/packages/front/src/fragments/Outliner/index.ts b/packages/front/src/fragments/Outliner/index.ts
index 91bfe8b2..5757e94b 100644
--- a/packages/front/src/fragments/Outliner/index.ts
+++ b/packages/front/src/fragments/Outliner/index.ts
@@ -234,7 +234,7 @@ export class Outliner extends OBC.Component implements OBC.Disposable {
       }
     }
 
-    this.detachAll(group);
+    this.detachAll(group, name);
     this._groups.delete(name);
 
     if (this.world) {
@@ -311,15 +311,15 @@ export class Outliner extends OBC.Component implements OBC.Disposable {
       if (!state) return;
       state.map = {};
       state.activeStyles.clear();
-      this.detachAll(state);
+      this.detachAll(state, group);
       if (group === DEFAULT_GROUP) this.cleanPoints();
       return;
     }
 
-    for (const [, state] of this._groups) {
+    for (const [name, state] of this._groups) {
       state.map = {};
       state.activeStyles.clear();
-      this.detachAll(state);
+      this.detachAll(state, name);
     }
     this.cleanPoints();
   }
@@ -537,7 +537,7 @@ export class Outliner extends OBC.Component implements OBC.Disposable {
     for (const [modelId, prev] of previouslyAttached) {
       const next = nextAttached.get(modelId) ?? new Set<THREE.Mesh>();
       for (const tile of prev) {
-        if (!next.has(tile)) pass.detachOutlinedTile(tile);
+        if (!next.has(tile)) pass.detachOutlinedTile(tile, name);
       }
     }
 
@@ -548,14 +548,14 @@ export class Outliner extends OBC.Component implements OBC.Disposable {
    * Detach every proxy this group has attached and clear the tracking
    * map. Used by `clean` and `remove`.
    */
-  private detachAll(state: OutlineGroupState) {
+  private detachAll(state: OutlineGroupState, group = DEFAULT_GROUP) {
     if (!this.world) {
       state.attached = new Map();
       return;
     }
     const pass = this.getRenderer().postproduction.outlinePass;
     for (const [, tiles] of state.attached) {
-      for (const tile of tiles) pass.detachOutlinedTile(tile);
+      for (const tile of tiles) pass.detachOutlinedTile(tile, group);
     }
     state.attached = new Map();
   }
@@ -576,7 +576,7 @@ export class Outliner extends OBC.Component implements OBC.Disposable {
       for (const [groupName, state] of this._groups) {
         const localIds = state.map[modelId];
         if (localIds && localIds.size > 0) {
-          void this.updateGroup(groupName);
+          this.updateGroup(groupName).catch(() => undefined);
         }
       }
     };