3.95 inch IL9488 LCD problem - bad display units or driver issue?

I have 2 3.5 inch LCD (IL9488) and 2 3.95 inch LCD (IL9486)
I have tried both in lvgl_esp32_port demo project and here is the issue I found with the 3.95 inch ones -

First IL9486 driver doesn’t work with them at all, after switch to IL9488, it does display the demo but with the following problem:

  1. the screen kind of flickers a bit.
  2. the color depths seems to be wrong, text, round corners shows aliasing even with anti-aliasing is on, also gradient shadow of a message box only shows 2 shades of grey and pink color.

Since I have 2 units of the display it’s unlikely both of them are faulty, also it’s not code/software issue as I can unplug it from the breadboard and plugin the 3.5 inch ones and they display the UI beautifully.

Any idea what might be wrong?


cc @Carlos_Diaz

adding a picture