Blurry featured Images on Illdy theme

My featured images are blurried ( at the moment the size of the image is 840x512 but I also tried all others formats)
I tried to:

  • Disable image compressor plugin
  • Change image size
  • Regenerate thumbnails with plugin
  • Change settings for image size (now is setted to 840x512)

Anyone that can help?

Thanks in advance

Hey there

Sorry about that, please always include link to your website in the question, I need to see the problem