Hello,
You can edit image sizes in function.php file. Find these lines:

function codeless_images_sizes(){
    
    add_image_size( 'port3', 600, 600, true );
    add_image_size( 'port3_grayscale', 927, 470, true );
    //add_image_size( 'port3_grayscale', 627, 470, true );
    add_image_size( 'port2', 460, 275, true );
    add_image_size( 'port2_grayscale', 940, 470, true );
    add_image_size( 'port4', 600, 600, true );

    add_image_size( 'blog', 825, 340, true );
    add_image_size( 'alternate_blog', 440, 195, true );
    add_image_size( 'alternate_blog_side', 355, 235, true );
    add_image_size( 'blog_grid', 350, 350, true );

    add_image_size( 'staff', 400, 270, true );
    add_image_size( 'staff_full', 500, 340, true );

}

edit the sizes of the portfolio you are using. Then upload again the images, and run a plugin that recreates thumbnails.

Best regards!