This is partly a question but partly a trouble report, because I did eventually get my sprite working, although I’m not sure why it stopped working or why it got fixed. Anyway…
I’ve started learning the new 2D features and had imported several png images as Sprites. I had several of them displayed in my scene when I switched platforms from PC/Mac/Linux to iOS; as soon as I switched platforms one of the displayed sprites stopped being visible. When I clicked that asset to check its import setting I found that while the import settings hadn’t changed, there was no longer a sprite created from that image.
I then resaved that image as a jpg and imported the new image as a sprite, and then that worked on all platforms. And then I resaved the image again back to a png and that sprite worked on all platforms. (for what it’s worth, this was a fullscreen 1024x768 image with no transparency)
Can anyone guess at why the image stopped working before? Is this simply a bug with switching platforms, or could there be some specific thing wrong about the image?