I have both a development environment and a production environment of a website. Both are identical.
On the production site, all post thumbnails show the full image instead of the resized image, even though the resized images are available. On the development site it's working perfectly fine.
The issue occurred after an update on the live site, in which some more images were set to new image sizes.
What I've checked/tried:
add_theme_support('post-thumbnails');exists and is set in the theme
- Regenerate all thumbnails (using the Regenerate Thumbnails plugin)
- Clear all caches
- File permissions are checked
- The images are being generated, just not shown
- Images are set properly
- Checked for differences in code between the different environments
- Updated / reinstalled WordPress
What could I be missing?