U2518D, LCD screen cracked

Dear community,

About half a year ago I bought the U2518D for a family member. After normal daily use, the screen started to show several cracks under the surface. These cracks result in a lot of damaged pixels, making the screen almost unusable. My initial thought was that there must have been some physical contact with the screen as you clearly see a point from where the cracks originate. However, the family member in question swears that no physical contact was made with the screen prior to the cracks showing up. I included a picture of the screen. Do you guys know if this could be some kind of manufacturing fault? Or is something like this only possible after physical contact with the screen?