Bug: Cover block stopped working

Hi,

I just noticed this today, but the cover blocks have stopped working.

If you go about 1/4 down the page on the link to help with, there is a pinecone image with the text not getting placed over it, rather it just comes in a gray box after the image. I have tried this on multiple pages, turned off all plugins and reset the theme and it still is happening for new pages/posts.

The really weird part is old posts that had it working previously still display correctly- as you can see on the live site https://arboretum.harvard.edu/plants/plant-exploration/2018-oregon-washington-expedition/. However, if we so much as update that page, it breaks like the newly created cover blocks. Both our staging and live sites are WP 5.7 and fully updated.

Thanks,
Matt

The page I need help with: [log in to see the link]