diff --git a/src/AcDream.App/UI/Layout/SelectedObjectController.cs b/src/AcDream.App/UI/Layout/SelectedObjectController.cs
index 1155f916..7076e794 100644
--- a/src/AcDream.App/UI/Layout/SelectedObjectController.cs
+++ b/src/AcDream.App/UI/Layout/SelectedObjectController.cs
@@ -180,6 +180,12 @@ public sealed class SelectedObjectController : IRetainedPanelController
             // flush against the slider at X=50 on the same row — the count
             // reads right-adjacent to the bar, retail's look. UiField
             // already supports it; the importer does not carry HJustify.
+            // OneLine is REQUIRED for the alignment: RightAligned only
+            // applies on the single-line draw path, and the multi-line
+            // path's per-keystroke scroll-extent churn was also the edit
+            // flicker the user reported. A 14 px numeric entry is
+            // single-line by construction.
+            _stackSizeEntry.OneLine = true;
             _stackSizeEntry.RightAligned = true;
             _stackSizeEntry.Selectable = true;
             _stackSizeEntry.ClearOnSubmit = false;