Vertical flickering background artifacts when LV_THEME_DEFAULT_DARK=1

[IvanVnucec]

LVGL version

v8.3

What happened?

I'm using Sunton CYD (Cheap Yellow Display) PlatformIo Board.
The project is based on the rzeldent/platformio-espressif32-sunton.
I've enabled LV_THEME_DEFAULT_DARK flag in the lv_conf.h and added simple button to the default screen and the screen had strange flickering artifacts (see image below).

I've also tried LV_THEME_DEFAULT_DARK=0 and the flickering disappears.
However, when I set darker grey background with lv_obj_set_style_bg_color(lv_scr_act(), lv_palette_darken(LV_PALETTE_GREY, 3), 0), there is a visible stripe flickering at x=0. Moreover, every darken palette besides level 0 and 1 has stripe flickering.

How to reproduce?

lv_conf.h:

#define LV_USE_THEME_DEFAULT 1
#if LV_USE_THEME_DEFAULT

    /*0: Light mode; 1: Dark mode*/
    #define LV_THEME_DEFAULT_DARK 1

    /*1: Enable grow on press*/
    #define LV_THEME_DEFAULT_GROW 0

    /*Default transition time in [ms]*/
    #define LV_THEME_DEFAULT_TRANSITION_TIME 80
#endif /*LV_USE_THEME_DEFAULT*/

main.cpp:

#include <Arduino.h>

#include <esp32_smartdisplay.h>
#include <lvgl.h>

void setup()
{
    smartdisplay_init();
    smartdisplay_lcd_set_backlight(1.0f);

    lv_disp_t *default_display = lv_disp_get_default();
    lv_disp_set_rotation(default_display, LV_DISP_ROT_270);

    // add button to the center
    lv_obj_t *btn = lv_btn_create(lv_scr_act());
    lv_obj_center(btn);
    lv_obj_t *label = lv_label_create(btn);
    lv_label_set_text_static(label, "Click me!");
}

void loop()
{
    lv_timer_handler();
}