Question HP Envy 27 monitor green and red flickering pixels all over screen

[Sporadicazmatic]

My monitor has green and red pixels flickering all over the screen at a fast rate. I had my MacBook connected to the monitor when it started flickering to black, every second or so. It did that for about 1 minute until the green and red pixels started flickering all over the screen.

The monitor does this with no display cables hooked up to it. I tried both HDMI ports, and same issue. I have reset the monitor to factory settings, plugged the power cable into a different outlets unplugged and plugged back in, shut off and on... Not sure what else to do. Any help is appreciated, thank you.

 

[Sporadicazmatic]

Update- just leaving the monitor on and using it with my laptop, the situation has become a lot less sever. I can still see a green pixel or 2 flicker on and off, nut it is very hard to notice. Does anyone know why this is doing this? Never buying a monitor off facebook marketplace again