Can not check limited warranty on iphone X

Hello everyone,

Today I got a problem that I can not understand even I already contacted with apple support but their answer did not help me at all. I don’t know why my iphone X with IOS 12.3.1 does not show up the limited warranty in setting section as the others have. It should be a new feature on IOS 12.2. Moreover, when I borrow another Iphone X from my friend then I accidentally touch the limited warranty line then it disappeared right away. I really want to know what happened to my phone as well as my friends phone. Does anyone get the same issue with me ?