Vertical lines after LCD replacement

Hello.

After LCD replacement the screen has some vertical lines and turns into white (you can still see everything) but has more white into it, and if i lock the device and wait 3-4 seconds and open it again the vertical lines disappear and the screen looks normal for a few seconds, but after it goes back to the white/vertical lines.

Is this a flex cable issue or a motherboard issue, does someone knows for sure?

Thank you.

Anyone with some Info about this?