I need help with AVIF files on iOS 16 Safari

Hey there. I'm having some problems with AVIF files on iOS 16. If you're reading this from an iPhone running iOS 16 you may see the problem.

I recently started using a new program called uploud to automate converting and uploading things like my hero images and slides to Backblaze B2, my storage provider. However, images that I make with github.com/Kagami/go-avif won't load on iOS 16 Safari. Here are the encoding settings I am using:

&avif.Options{
	Threads: runtime.GOMAXPROCS(0),
	Speed:   0,
	Quality: 48,
}

This creates images that can be viewed in Chrome:

But not on iOS 16:

What am I doing wrong? I get no useful debug information from the browser inspector on Safari. It just says the image is wrong but won't tell me why.

Please contact me if you have any ideas.