AOMediaCodec/av1-avif#180 changed standard(https://aomediacodec.github.io/av1-avif/#layer-selector-property) to require a lsel box with layer_id set to 0xFFFF in an avif image to allow progressive decoding. Updated test images are yet to be merged: AOMediaCodec/av1-avif#191.
With this change, mp4parse will reject any progressive image due to lsel being a mandatory unsupported box. We should at least be able to decode these images non-progressively.
I hope this can get into Firefox 102 ESR release, or we have to wait very long before being able to safely serve progressive AVIF images.