Dropzone: thumbnails are not visible consistently on Storybook

[silvalaura]

Describe the bug When uploading files to Dropzone on Storybook, with the thumbnails prop set to true, sometimes the thumbnail appears and sometimes it's just blank.

To Reproduce Steps to reproduce the behavior:

1. Go to Storybook (https://storybook-preview-dev--upbeat-sinoussi-f675aa.netlify.app/?path=/story/dropzone--default)
2. Browse a few files
3. Notice that sometimes the thumbnail is visible, sometimes it's not.

Expected behavior Thumbnails are visible consistently when the prop is set to true.

Screenshots

Additional context When adding files sometimes, there is a console error Failed to load resource: net::ERR_FILE_NOT_FOUND. Not sure if this is a limitation of Storybook, or why this happens only sometimes.