My iPhone 11 dropped into water and they saying that if iPhone drop water after changing the screen the Face ID will not work again
My Face ID is not working due to changing of screen after it dropped into water
iPhone 11
It will never work again.
A liquid damaged device is not considered repairable at all by Apple.
Only Apple or an authorized service provider has the necessary tools to replace the display and retain the use of faceid, and since Apple will not do so on a liquid damaged device, you’ve rendered your phone untouchable by Apple.
You can live with the problem, or recycle it and buy a new phone. You have forfeited your right to a discounted out of warranty replacement by tampering with it.