MacBook Pro Touch Bar Not Lighting Up?

I am using MacBook Pro 2018 model. Suddenly my Touch Bar is lighting up.

It is working fine but there is no light in Touch Bar.

For example: If I try to touch on finger print(power), escape button, they are working fine. I can guess and touch the other buttons like volume, brightness they are working fine but Touch Bar is not lighting up.

I have discussed this issue with Online support team and provided logs/video but they are not sure about the problem.

Basic steps carried out:

- Checked All Keyboard Settings, Power Saver Settings, any Setting involving the keyboard, power, etc.

- Reset SMC, Reset PRAM, Reset NVRAM.

- Performed Restart then COMMAND+R Disk Utility, Formatted Hard Drive and Reinstalled macOS.

Today I visited the Apple care centre and performed the diagnostic but it is showing "No issues found in Hardware".

Can anyone help me to resolve this issue?