diff --git a/web/oss/src/components/Playground/Components/PlaygroundVariantConfig/index.tsx b/web/oss/src/components/Playground/Components/PlaygroundVariantConfig/index.tsx
index 90e2bf80ee..0d943a1480 100644
--- a/web/oss/src/components/Playground/Components/PlaygroundVariantConfig/index.tsx
+++ b/web/oss/src/components/Playground/Components/PlaygroundVariantConfig/index.tsx
@@ -217,6 +217,10 @@ const PlaygroundVariantConfig: React.FC<
                                 revisionId={variantId}
                                 onRefinePrompt={handleRefinePrompt}
                                 viewMode={viewMode}
+                                // Embedded (drawer) renders the variant config
+                                // header non-sticky, so the section headers have
+                                // nothing to clear — pin them at the scroll top.
+                                stickyHeaderTop={embedded ? 0 : 48}
                             />
                         </PlaygroundNodeTokenPathProvider>
                     </FieldsDetectionProvider>
diff --git a/web/packages/agenta-entity-ui/src/DrillInView/components/PlaygroundConfigSection.tsx b/web/packages/agenta-entity-ui/src/DrillInView/components/PlaygroundConfigSection.tsx
index 0618b14bd8..a77bcad86e 100644
--- a/web/packages/agenta-entity-ui/src/DrillInView/components/PlaygroundConfigSection.tsx
+++ b/web/packages/agenta-entity-ui/src/DrillInView/components/PlaygroundConfigSection.tsx
@@ -451,6 +451,15 @@ export interface PlaygroundConfigSectionProps {
     onRefinePrompt?: (promptKey: string) => void
     /** View mode controlled from parent (form/json/yaml) */
     viewMode?: ConfigViewMode
+    /**
+     * Top offset (px) for the sticky section headers. Defaults to 48 to clear
+     * the sticky `PlaygroundVariantConfigHeader` (h-[48px], `sticky top-0`) that
+     * sits above the config in the full playground. In the embedded drawer that
+     * header is rendered non-sticky (`grow`), so there is nothing to clear —
+     * pass 0 there to keep the section headers flush with the scroll top instead
+     * of floating 48px down into the editor content.
+     */
+    stickyHeaderTop?: number
 }
 
 function PlaygroundConfigSection({
@@ -461,6 +470,7 @@ function PlaygroundConfigSection({
     moleculeAdapter,
     onRefinePrompt,
     viewMode: externalViewMode,
+    stickyHeaderTop = 48,
 }: PlaygroundConfigSectionProps) {
     const {llmProviderConfig} = useDrillInUI()
 
@@ -1362,7 +1372,8 @@ function PlaygroundConfigSection({
 
             return (
                 <div
-                    className="flex items-center justify-between w-full px-3 py-2 bg-[var(--ag-c-FAFAFB)] cursor-pointer select-none sticky top-[48px] z-[2]"
+                    className="flex items-center justify-between w-full px-3 py-2 bg-[var(--ag-c-FAFAFB)] cursor-pointer select-none sticky z-[2]"
+                    style={{top: stickyHeaderTop}}
                     onClick={() => toggleSection(fieldKey)}
                 >
                     <div className="flex items-center gap-1">
@@ -1578,7 +1589,10 @@ function PlaygroundConfigSection({
             ) : (
                 <>
                     {!hasTopLevelObjectSection && (
-                        <div className="flex items-center w-full px-3 py-2 bg-[var(--ag-c-FAFAFB)] sticky top-[48px] z-[2]">
+                        <div
+                            className="flex items-center w-full px-3 py-2 bg-[var(--ag-c-FAFAFB)] sticky z-[2]"
+                            style={{top: stickyHeaderTop}}
+                        >
                             <span className="capitalize font-medium text-sm">Config</span>
                         </div>
                     )}
diff --git a/web/packages/agenta-ui/src/Editor/plugins/code/utils/pasteUtils.ts b/web/packages/agenta-ui/src/Editor/plugins/code/utils/pasteUtils.ts
index 39c12219d0..10f0055617 100644
--- a/web/packages/agenta-ui/src/Editor/plugins/code/utils/pasteUtils.ts
+++ b/web/packages/agenta-ui/src/Editor/plugins/code/utils/pasteUtils.ts
@@ -117,8 +117,13 @@ export function $insertLinesWithSelectionAndIndent({
         }
     }
 
-    // Clone trailing lines before removal
-    const clonedTrailingLines = linesAfter.map((l) => $copyNode(l))
+    // Capture trailing-line TEXT before removal, then rebuild fresh nodes after
+    // insertion (see re-insertion below). We can't element-clone these lines:
+    // `$copyNode` assigns the clone a fresh key, and Lexical's ElementNode only
+    // carries child pointers when the key is unchanged — so a cloned CodeLineNode
+    // comes back EMPTY, wiping every line below the paste point. Rebuilding from
+    // text mirrors the large-paste fast path and preserves the content faithfully.
+    const trailingLineTexts = linesAfter.map((l) => l.getTextContent())
     linesAfter.forEach((l) => l.remove())
     // Remove current line
     currentLine.remove()
@@ -174,11 +179,12 @@ export function $insertLinesWithSelectionAndIndent({
         insertIdx++
     }
 
-    // Add trailing lines (use clones)
-    clonedTrailingLines.forEach((l, i) => {
+    // Add trailing lines (rebuilt from captured text — see note above)
+    const trailingLanguage = parentBlock.getLanguage()
+    trailingLineTexts.forEach((text, i) => {
         const prevChild = $getLineAtIndex(parentBlock, insertIdx - 1 + i)
         if (prevChild) {
-            prevChild.insertAfter(l)
+            prevChild.insertAfter($createNodeForLineWithTabs(text, trailingLanguage))
         }
     })
 
diff --git a/web/packages/agenta-ui/src/SharedEditor/SharedEditorImpl.tsx b/web/packages/agenta-ui/src/SharedEditor/SharedEditorImpl.tsx
index 8c6a2e027f..ab93140354 100644
--- a/web/packages/agenta-ui/src/SharedEditor/SharedEditorImpl.tsx
+++ b/web/packages/agenta-ui/src/SharedEditor/SharedEditorImpl.tsx
@@ -453,12 +453,24 @@ const SharedEditor = ({
             style={
                 {
                     ...props.style,
-                    interpolateSize: "allow-keywords",
                     height: "var(--editor-h, auto)",
                     overflow: "hidden",
-                    transitionProperty: "height",
-                    transitionDuration: "300ms",
-                    transitionTimingFunction: "cubic-bezier(0.4, 0, 0.2, 1)",
+                    // The height transition exists only to animate the collapse
+                    // toggle (which sets `--editor-h` to a fixed px ↔ auto). Code
+                    // editors never use that toggle, so `--editor-h` stays `auto`
+                    // and `interpolate-size: allow-keywords` would instead animate
+                    // EVERY content-height change while typing/pasting — making the
+                    // editor grow over 300ms and lurching the surrounding drawer's
+                    // scroll. Disable the animation for codeOnly so growth is
+                    // instant; keep it for the collapsible rich-text/prompt editors.
+                    ...(editorProps?.codeOnly
+                        ? {}
+                        : {
+                              interpolateSize: "allow-keywords",
+                              transitionProperty: "height",
+                              transitionDuration: "300ms",
+                              transitionTimingFunction: "cubic-bezier(0.4, 0, 0.2, 1)",
+                          }),
                 } as React.CSSProperties
             }
             onPasteCapture={handlePasteCapture}