I think you have a defective card. If you can't solve the problem, then try taking it back to where you got it from.
I got the graphics card from newegg.com and it's past the time frame for me to send it back and would need to go through the manufacturer which is Gigabyte.
Have you tried reseating the GPU, and have you tried a different monitor? Keep an eye on your GPU temps as well.
I've reseated the gpu, changed to a different monitor and the gpu temp is normal when it's gone to a blank screen.
Get some more RAM ( 16 or more), New CPU ( AMD Ryzen 7 2700 or more, maybe 5. I'm not familiar with Intel), New GPU ( Minimum nvidia 1080 Ti , Recommended nvidia GTX 1660) And a SSD ( 500 GB or more, It depends on how much memory you want)