Vertical red line on the display after two months of purchase

[Kanden]

Good morning, after two months of purchase of my HP All-in-one 24 - g013nl appeared a vertical red line on the screen. Sent to support the PC with pictures related to the problem, in Hungary, I live in Italy. The PC support sends me back the same as before always with the red line on the screen. Call the call center (in Serbia) and tell me that the assistance did not see the problem, after which instead are the signs of opening of the body and the red line, and more nuanced but this, probably have tried to delete it without success. I ask if they can replace it, if they are unable to repair it, but the procedure does not have it.
What is the problem ?
Because after two months appears a red line on the screen?
What are the causes?
Why not fix it?
Thank you

[MKazi]

@Kanden

I have brought your issue to the attention of an appropriate team within HP. 

They will likely request information from you in order to look up your case details or product serial number. 
Please look for a private message from an identified HP contact. 

Additionally, keep in mind not to publicly post personal information (serial numbers and case details).

Thank you for visiting the HP Support Forum

[Kanden]

The unit has been repaired, the red vertical line was removed.

I use Hp for many years and I know the high professionalism of its employees.

Thank you Christopher for the courtesy and professionalism
Executive Customer Relations
HP Inc.
Palo Alto, California

but also thank you Anna for the courtesy and professionalism
HP Inc Customer Relations Team Italy

Best regards