Macbook Pro 2012 Graphical artifacts

[JustWantIT]

Hello there! I recently buyed an used macbook pro 2012 13 i5. But then i wake it up or closing and opening sceen, i see graphical artifcats, wihch are or a thick horizontal gray line, half of white screen with apple logo. Its happens only for a milisecond but im still woried. The strange thing is that i tested it in 3D benchmark, video (2k and 1080 60 fps), mac os and other apps...Everything with that was fine. So...Any ideas?

Video link:
https://drive.google.com/file/d/1AQupJ8PNV66Ttuxz62dJyQ50XsVLFvLX/view?usp=sharing

 

[tubeexperience]

I don't see anything

 

[JustWantIT]

I don't see anything

https://drive.google.com/file/d/1AQupJ8PNV66Ttuxz62dJyQ50XsVLFvLX/view?usp=sharing

Here is video version.

 

[tubeexperience]

https://drive.google.com/file/d/1AQupJ8PNV66Ttuxz62dJyQ50XsVLFvLX/view?usp=sharing

Here is video version.

I don't think this a concern.

 

[JustWantIT]

I don't think this a concern.

tomorrow i will upload more, wihch looks worse

 

[JustWantIT]

PROBLEM SOLVER. HIGH SIERRA CREATES THIS BUG/LAG