Hello , I have same Problems.My screen is also white.
I use this screen .
https://www.aliexpress.com/item/32538935176.html?spm=a2g0s.9042311.0.0.729f4c4diFbbDT
This is 3.5" LCD for Arduino Mega 2560 with 16 bit shield ( Picture is attached).
It uses ILI 9486/ILI 9588 driver.
For testing I use examples and libraries from :http://www.lcdwiki.com/3.5inch_Arduino_Display-Mega2560
I verify the Examples without Errors but after download to Mega nothing happens .
Have somebody this Display and please show me one example .
