What is wrong with my screen?

Okay, so I actually have the LG Stylo 4. I just activated it yesterday, and only dropped it once. Not from a very far distance. The screen isn’t cracked at all, but I get this weird, (the only way to describe it is filter), over the screen. Like with vertical white lines, like something off of Instagram almost? It makes the screen very difficult to see. I don’t have any sort of display settings that say anything about a filter except the blue light, which when it’s on or off, the filter still shows up. And when I lock my phone and leave it for a bit, it disappears, but reappears when I start to use my phone again! I’ve been all over google, and no one seems to have the same problem. Most of it is just about cracked screens with lines, but my screen isn’t cracked at all.