Image Size Issues

I am using gravity forms for user generated uploads on my website. Having some serious issues getting the settings to work properly for images uploaded. My goal is for every image to upload at 728 x 510.

I have made a few changes to the functions.php and added some css code, however, I cant get it right. Images are being cropped among other issues. And now it takes a long time for uploads. I also have a plugin to add a watermark for every image, not sure if that affects anything.

Can someone please help me figure out this simple task…

Here are my CSS additions
.image-overlay { display: none!important; }
.big-preview.single-big{ text-align: center; }
.big-preview.single-big a{ display: inline-block; }
#respond .comment-form-email, #respond .comment-form-url {
display: none;
}
.inner_sidebar {
margin-left: 15px;
}
.sidebar section {
padding: 18px 0;
}
.content, .sidebar { padding-top: 18px; padding-bottom: 18px; }
h2.post-title.entry-title:hover {
text-decoration: underline;
}

Here are the changes in functions.php
$avia_config[‘imgSize’][‘entry_with_sidebar’] = array(‘width’=>728, ‘height’=>728, array(top, center)); // big images for blog and page entries
$avia_config[‘imgSize’][‘entry_without_sidebar’]= array(‘width’=>728, ‘height’=>728, array(top, center)); // images for fullsize pages and fullsize slider

https://www.ads-software.com/plugins/gravityforms-nl/