Hi Christopher,
The fixed positioning of the background is only applicable to the parallax type of background. You should remove it if you only intend to display its background without parallax. Removing it should fix the issue of missing backgrounds on the iPad.
You’re correct about that it’s based upon screen resolution, and it’s not CSS issue at all. Let’s say we’re referring to iPad Mini 1st Gen, this is the specs

It has 1024px screen resolution similar to 13-15 inch desktop monitor, or a laptop. In fact, 1024px is still considered a desktop resolution. A tablet is something in between mobile and desktop, which shares the same boundary depending on orientation, which is why you’re seeing desktop specific views on landscape orientation.
The hide-during-breakpoints feature is just a generic breakpoint(common boundaries between devices) because it’s not possible to include all devices.
A tablet given with a keyboard can be a laptop and a touch laptop with a removable keyboard can be a tablet, this issue is not just limited to iPad Mini. And this limitation is not fixable by CSS nor Javascript, because there is no way to tell what kind of device the browser is running under, it can’t tell if it’s a laptop used as a tablet, or a tablet used as a laptop/desktop.
If you intend to hide desktop elements from tablet then I recommend hiding them from laptop breakpoints, since both tablets and laptops share the same 1024px resolution. The downside, tablet elements will appear on the laptop as well.
Thanks!