Fix #3122

If the feedrate multiplier is changed while the print is paused
update the saved feedrate multiplier in RAM

Firmware/Marlin.h

@@ -378,6 +378,10 @@ void save_print_file_state();
 void restore_print_file_state();
 void save_planner_global_state();
 void refresh_print_state_in_ram();
+
+/// Updates the feedrate multiplier when a print is saved such that
+/// it is not overwritten when the print is later resumed
+void refresh_saved_feedrate_multiplier_in_ram();
 void clear_print_state_in_ram();
 extern void stop_and_save_print_to_ram(float z_move, float e_move);
 void restore_extruder_temperature_from_ram();

Firmware/Marlin_main.cpp

@@ -10562,6 +10562,15 @@ void refresh_print_state_in_ram()
     isPartialBackupAvailable = true;
 }
 
+void __attribute__((noinline)) refresh_saved_feedrate_multiplier_in_ram() {
+    if (!saved_printing) {
+        // There is no saved print, therefore nothing to refresh
+        return;
+    }
+
+    saved_feedmultiply2 = feedmultiply;
+}
+
 void clear_print_state_in_ram()
 {
     // Set flag to false in order to avoid using

Firmware/ultralcd.cpp

@@ -714,6 +714,7 @@ void lcd_status_screen()                          // NOT static due to using ins
         if (initial_feedmultiply != feedmultiply) {
             feedmultiply = constrain(feedmultiply, 10, 999);
             lcd_encoder = 0; // Consume rotation event
+            refresh_saved_feedrate_multiplier_in_ram();
         }
     }
 #endif //ULTIPANEL_FEEDMULTIPLY
@@ -5434,6 +5435,9 @@ static void lcd_tune_menu()
 	SilentModeMenu = eeprom_read_byte((uint8_t*) EEPROM_SILENT);
 
 	MENU_BEGIN();
+	ON_MENU_LEAVE(
+		refresh_saved_feedrate_multiplier_in_ram();
+	);
 	MENU_ITEM_BACK_P(_T(MSG_MAIN));
 	MENU_ITEM_EDIT_int3_P(_i("Speed"), &feedmultiply, 10, 999);////MSG_SPEED c=15