I’ve come across this a couple of times now, you’ve set an SVG as a background image, and all is fine until you look at it on an Apple device; the SVG mysteriously doesn’t show.
The simple fix is to make sure you are declaring background-size before background-position in the CSS.
It may be something do with the order shorthand background properties should be declared. I’m not sure, but it’s one of those little things that can cost you time and drive you crazy. I drove me crazy for a short while the first time, so I hope this helps your sanity.