Please regulate the battery voltage to a stable 12v. Batteries don't have constant voltage! Also check for any damage to the battery.

I have this simple code with lvgl adapter:
#include <esp_lcd_panel_dev.h>
#include <esp_lcd_panel_commands.h>
#include <esp_lcd_st7703.h>
#include <esp_lcd_panel_st7789.h>
#include <esp_lcd_panel_io.h>
#include <esp_ldo_regulator.h>
#include <esp_lcd_panel_io_interface.h>
#include <esp_lcd_mipi_dsi ...