수정3

frontend/src/utils/indicatorRegistry.ts

@@ -445,7 +445,7 @@ export function mergePlotDefs(saved: PlotDef[] | undefined, defaults: PlotDef[])
 /** OBV·CCI·RSI·TRIX — 이중 plot 병합·표시 보장 */
 const SIGNAL_LINE_INDICATOR_TYPES = new Set(['OBV', 'CCI', 'RSI', 'TRIX']);
 
-function normalizeDualLinePlotDef(saved: PlotDef, reg: PlotDef): PlotDef {
+function normalizeDualLinePlotDef(saved: PlotDef, reg: PlotDef, defaultLineStyle?: HLineStyle): PlotDef {
   return {
     ...reg,
     ...saved,
@@ -453,7 +453,7 @@ function normalizeDualLinePlotDef(saved: PlotDef, reg: PlotDef): PlotDef {
     title: reg.title,
     type: 'line',
     lineWidth: Math.max(1, saved.lineWidth ?? reg.lineWidth ?? 1),
-    lineStyle: saved.lineStyle ?? reg.lineStyle ?? 'solid',
+    lineStyle: saved.lineStyle ?? defaultLineStyle ?? reg.lineStyle ?? 'solid',
     color: resolvePlotLineColor(saved.color, reg.color),
   };
 }
@@ -474,7 +474,8 @@ function normalizeSignalLineIndicatorPlots(
     const nextPlots = merged.map(p => {
       const reg = registryPlots.find(r => r.id === p.id);
       if (!reg) return p;
-      return normalizeDualLinePlotDef(p, reg);
+      const defaultLineStyle = p.id === 'plot1' ? 'solid' as const : undefined;
+      return normalizeDualLinePlotDef(p, reg, defaultLineStyle);
     });
     nextPlots.sort((a, b) => {
       const order = ['plot0', 'plot1'];