Enable button debouncing also in modal mode (!lcd_update_enabled). In lcd_clicked() consume click event immediately.

Firmware/lcd.cpp

@@ -686,7 +686,11 @@ LongTimer lcd_timeoutToStatus;
 uint8_t lcd_clicked(void)
 {
 	bool clicked = LCD_CLICKED;
-	if(clicked) lcd_button_pressed = 0;
+	if(clicked)
+	{
+	    lcd_button_pressed = 0;
+	    lcd_buttons &= 0xff^EN_C;
+	}
     return clicked;
 }
 
@@ -766,8 +770,7 @@ void lcd_buttons_update(void)
 	uint8_t newbutton = 0;
 	if (READ(BTN_EN1) == 0)  newbutton |= EN_A;
 	if (READ(BTN_EN2) == 0)  newbutton |= EN_B;
-	if (lcd_update_enabled)
+
-	{ //if we are in non-modal mode, long press can be used and short press triggers with button release
     if (READ(BTN_ENC) == 0)
     { //button is pressed
         lcd_timeoutToStatus.start();
@@ -776,12 +779,11 @@ void lcd_buttons_update(void)
             safetyTimer.start();
             if ((lcd_button_pressed == 0) && (lcd_long_press_active == 0))
             {
-					longPressTimer.start();
+                //long press is not possible in modal mode
+                if (lcd_update_enabled) longPressTimer.start();
                 lcd_button_pressed = 1;
             }
-				else
+            else if (longPressTimer.expired(LONG_PRESS_TIME))
-				{
-					if (longPressTimer.expired(LONG_PRESS_TIME))
             {
                 lcd_long_press_active = 1;
                 if (lcd_longpress_func)
@@ -789,7 +791,6 @@ void lcd_buttons_update(void)
             }
         }
     }
-		}
     else
     { //button not pressed
         if (lcd_button_pressed)
@@ -805,12 +806,6 @@ void lcd_buttons_update(void)
         else
             lcd_long_press_active = 0;
     }
-	}
-	else
-	{ //we are in modal mode
-		if (READ(BTN_ENC) == 0)
-			newbutton |= EN_C; 
-	}
 
 	lcd_buttons = newbutton;
 	//manage encoder rotation

Firmware/menu.cpp

@@ -236,6 +236,8 @@ uint8_t menu_item_function_P(const char* str, menu_func_t func)
 		if (menu_clicked && (lcd_encoder == menu_item))
 		{
 			menu_clicked = false;
+            lcd_button_pressed = 0;
+            lcd_buttons &= 0xff^EN_C;
 			lcd_update_enabled = 0;
 			if (func) func();
 			lcd_update_enabled = 1;

Firmware/ultralcd.cpp

@@ -463,6 +463,8 @@ static uint8_t menu_item_sdfile(const char*
 		}
 		if (menu_clicked && (lcd_encoder == menu_item))
 		{
+		    lcd_button_pressed = 0;
+		    lcd_buttons &= 0xff^EN_C;
 			menu_action_sdfile(str_fn);
 			return menu_item_ret();
 		}