Temporarily broken images silently clears Image Blocks

In WordPress 6.0-RC2, editing a page that has Image Blocks that refers to a temporarily unavailable image, silently clears the affected image blocks.

Issue raised on the Gutenberg repo:
https://github.com/WordPress/gutenberg/issues/41161

I think this has the potential to be really annoying to users. If your CDN is unavailable for any reason, you can’t edit any WordPress page that has an Image Block using images from the CDN. Opening such a page in the block editor will clear out the affected image blocks and then saving it will make the change permanent.