If anyone else is looking for a solution to removing <p> tags from around images, in the ACF WYSIWYG editor, just use the following code in your functions:
function filter_ptags_on_acf_images($acfcontent){
return preg_replace('/<p>\s*(<a .*>)?\s*(<img .* \/>)\s*(\/a>)?\s*<\/p>/iU', '\1\2\3', $acfcontent);
}
add_filter('acf_the_content', 'filter_ptags_on_images');