Hi ksuna24,
The default featured image size is 670 * 300, So if you update bigger size than this then the featured image will automatically crop the image size into 670 * 300, IF you want changes on the size of image then the code is inside theme folder -> functions.php
// Add Interface Pro custom image sizes
add_image_size( 'featured', 670, 300, true );
add_image_size( 'featured-medium', 230, 160, true );
add_image_size( 'slider-narrow', 1038, 500, true ); // used on Featured Slider on Homepage Header for narrow layout
add_image_size( 'slider-wide', 1440, 500, true ); // used on Featured Slider on Homepage Header for wide layout
add_image_size( 'gallery', 474, 342, true ); // used to show gallery all images
add_image_size( 'icon', 100, 100, true ); //used for icon on business layout
We recommended you to create a child theme before making any changes on it.
Thank you!