I have noticed when connecting screens like the FT813, on AVR boards like the MEGA, the 3.3V regulator turns out to be not so efficient, from 5" the power demand by the backlight begins to make the MCU suffer. I have seen that screens like the FT813-5" or the FT813-7" from Riverdi behave erratically and sometimes disconnect the arduino MEGA from the PC. The original library for gameduino 23X is designed to take full advantage of AVR boards, but using selected screens for its low consumption.
The boards that have turned out to be the most stable so far are: teensy 3.6, teensy 4, teensy 4.1, black STM32F407VG, black F411CE, even the bluePill F103CB performed very well. In all of them it is convenient to power the backlight through an independent USB line, if possible, a USB-C adapter can be used, with the idea of ​​being able to use a USB cable of this type
MicroUSB to USB-C

NHD 7" on teensy 4.1

I can test with a teensy 3.2, which fails with a 4.3" FT813 NHD screen, when I connect the backlight to the teensy, I plan to spring a section of a microUSB cable and install a USB-C adapter, with the idea of ​​powering the backlight and teensy 3.2 with a single USB-C cable. As soon as I get the missing parts I share the result, I trust it will work based on the result with the 7" NHD screen.
Cross your fingers