LVGL in ESP32 WROOM

[sergiomarina]

I'm reusing a 2021's code (including ESP32 and ILI9341 pin out) developed in IDF4.0.
In IDF5.0 with the LGVL old environment, the display does not show as expected. Please, refer to the 2 attached screenshots. The picture "FirstImage.jpg" shows the initial image and the picture "RefreshAfterFirstImage.jpg" represents the image after the first refresh and remains steady.
The expected result should be just the number '15.2' at the screen center.

The display and the ESP32 has been changed with spares, without improvements. Therefore I exclude to suffer a HW fault.

I'm wondering if somehow my problem is familiar to someone.
Please, ask me more info if needed to figure out the issue.
Thank you.

Added on May the 28th
I found an old executable (IDF 4.0 and corresponding LVGL library). I tested the monitor and it works fine. I'm now 99% sure the attached screenshots reports an issue related to SW.

Just tested the combination of ESP-IDF4.2 and 'github.com/lvgl/lv_port_esp32' library and the issue remains as it was, without any changes.
I also tested a different power supply. No improvements.
Based on the attached pictures, has someone an idea of what I could check in depth?
thx!

one week after: changed in MENUCONFIG the color depth from 8 to 16 and the issue was solved.