Bug Description

I recently moved hosts returning to wordpress.com.
I've been using the Modern Image Formats plugin since release without issue.

However, since the site move whenever I upload a new image in the editor I get an error: "This image has an empty alt attribute; its file name is G0061259-1024x768.webp"

which is weird because the plugin re-names the file with -jpg- The block should be looking for G0061259-jpg-1024x768.webp or whatever image resolution was produced. The error occurs on all file resolution sizes except 'original' which displays correctly in the editor.

All images however display correctly on the front end.

Steps to reproduce

1. Go to wordpress.com hosted blog
2. Install the Modern Image Formats plugin
3. Upload an image in the editor
4. See error

Screenshots

Additional Context

WordPress 6.6.1
PHP 8.1
Gutenberg 19.0.0

Whatever the wordpress.com Business hosting plan standard Nginx plan setting are.

Existing files and pages pre move have no issues. Only new uploads.

Selecting 'Outputi JPEG images in addition to the modern format' solves the issue in the editor, webp images display on the front end.
But this isn't too sustainable long term imo.