featured image : Grey bars

In the grid (https://www.scholengemeenschap-beerse.be/) my image is displayed correct
but i want to align it left (not centered).

In “read more” (https://www.scholengemeenschap-beerse.be/blog-post/update-maatregelen-vanaf-maandag-25-januari-2021/) my image is cropped and i see grey bars beside.

How can I correct both issues ?

My current CSS :

.featured-content {padding-left: 50px;}

.site-main .widecolumn {
margin-left: 50px;
margin-right: 15%;
}

.site-content {
margin-left: 50px;
margin-right: 30%;
}

.site:before {width: 0;}

#secondary {width: 0;}

.grid-blog-thumb{background: #fff !important;}
.grid-blog-thumb img {object-fit: contain;object-position: left;}
.grid-blog-thumb image{margin:0 !important;}
.grid-blog-thumb{width:auto !important;}

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