refactor: Update BB calculation with ffill() and debug print

src/pages/backtesting/backtesting_page.py

@@ -80,10 +80,14 @@ class DynamicStrategy(Strategy):
                     middle_col = bb_result.columns[1]  # BBM
                     lower_col = bb_result.columns[0]  # BBL
                     
-                    # Extract and process the values
+                    # Extract and process the values using ffill() instead of fillna(method='ffill')
-                    upper = bb_result[upper_col].fillna(method='ffill').fillna(0).values
+                    upper = bb_result[upper_col].ffill().fillna(0).values
-                    middle = bb_result[middle_col].fillna(method='ffill').fillna(0).values
+                    middle = bb_result[middle_col].ffill().fillna(0).values
-                    lower = bb_result[lower_col].fillna(method='ffill').fillna(0).values
+                    lower = bb_result[lower_col].ffill().fillna(0).values
+                    
+                    # Add debug print to verify values
+                    if len(upper) > 0:
+                        print(f"Debug BB values - Upper: {upper[-1]:.2f}, Middle: {middle[-1]:.2f}, Lower: {lower[-1]:.2f}")
                     
                     return upper, middle, lower