next/image default placeholder is empty (blur off), if you want to put something as a placeholder while the images load you can add a class to the component something like
import NextImage from 'next/image' //next component name it whatever
import styles from 'styles/mycss.module.css' //path to css file
<NextImage src="/url" className={styles.nextImageBackground} layout="fill"/>
//css file
.nextImageBackground{
background-image: url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCA1MTIgNTEyIj48cGF0aCBkPSJNMjI0IDM4Ny44MTRWNTEyTDMyIDMyMGwxOTItMTkydjEyNi45MTJDNDQ3LjM3NSAyNjAuMTUyIDQzNy43OTQgMTAzLjAxNiAzODAuOTMgMCA1MjEuMjg3IDE1MS43MDcgNDkxLjQ4IDM5NC43ODUgMjI0IDM4Ny44MTR6Ii8+PC9zdmc+')
}