Index gallery image ratio issue

Hi I am using the Flatiron template and on the Index gallery (currently my homepage) the horizontal 2:1 images are scaling down by 50% but the square and vertical images are remaining at 100% (in proportion to their original sizes) Is there a CSS code that overrides this and allows the horizontal images to remain at 100% i.e run across two columns? 

Any help would be much appreciated.

url rsdm.com.au
 

The url is https://www.rsdm.com.au

I have tried adding this code CSS code via Website Tools, Custom CSS  but it does nothing.

 

/* Ensure images in the homepage index gallery maintain equal proportions */
.index-gallery img {
    object-fit: cover;
    width: 100%;
    height: auto;
}

/* Optional: set a max height to ensure uniformity across images of different ratios */
.index-gallery img {
    max-height: 300px; /* adjust this value as needed */
}

/* Additional styling to ensure consistent spacing and layout */
.index-gallery {
    display: flex;
    flex-wrap: wrap;
    justify-content: center; /* center the images in the gallery */
}

.index-gallery-item {
    margin: 10px; /* adjust spacing between images as needed */
    overflow: hidden; /* hide any overflow */
}
 

@BeyondSpace  all the information you keep asking for is in the original post? 

Sorry for misunderstanding, but as I checked the images, the 2:1 ones still functioning for me