Thumbnails images stretched after 6.0.3 update

[ivanjeronimo]

I'm using a thumbnail loop block to show blog posts on the homepage of my blog.

After the 6.0.3 update, the images got stretched (disproportionately scaled to fit the thumbnail dimensions instead of cropping).

This only happens in publication mode. Images are normal when editing.

Homepage at:
​https://ivanjeronimo.com.br/

[joyously]

I think this problem is already being tracked in #56855.

[ivanjeronimo]

Duplicate of #56855.