Check its position, if it doesn't work use this and change it with your own values "background-image:linear-gradient(180deg, black -119px, #2f495c, #60809b)"
Try just "background" instead of "background-image"? This is what I have for my gradient BGs and it works: "background: linear-gradient(130deg, rgba(0,0,0,1) 0%, rgba(128,128,128,1) 25%, rgba(61,38,97,1) 50%, rgba(144,29,34,1) 100%);"
i misread. but the reason is probably because there's a lot to load