The Divi builder has a tiny screen. Add this to the functions.php of your child theme to make it full screen.

// Make a full screen Divi builder
add_action('admin_head', 'full_screen_page_builder');
function full_screen_page_builder() {
echo '<style>
.et_pb_modal_settings_container {
width: 100% !important;
padding: 0 !important;
margin: 0 !important;
left: 0 !important;
height: 95% !important;
top: 35px;
}
.et-pb-options-tabs-links {
width: 100% !important;
}
.et_pb_prompt_modal{
top: 35px !important;
height: 95% !important;
left: 15% !important;
width: 95% !important;
}
.et_pb_prompt_modal_save_library {
margin-left: -12% !important;
height: 80% !important;
}
/* increase html editor to 500px high, credits Terry Smith */
#et_pb_content_new_ifr{
height:500px!important
}
</style>';
}
Code language: HTML, XML (xml)