After analyzing the original backlight connections, it became clear why it fails: the Chinese designers who created the display wanted to save space and money by connecting the LEDs in parallel.

However, since each LED has a slightly different threshold voltage, one of them draws more current and fails prematurely. The remaining two LEDs then experience even higher currents and burn out soon afterwards.

To address this issue, I decided to change the connection according to the lower schematic. I shorted the original 22R resistors and put a 220R resistor in series with each new LED.