I've read the patch notes about moving the Custom Layout Update to a layout file in Magento 2.3.4 so I thought I was doing this correctly but something must be off because I still don't see the option under the Design->Custom Layout Update for this CMS page.
I'm really just looking to add a JS file to this single CMS page. Here's my code:
/app/design/frontend/Vendor/Theme/Magento_Cms/layout/cms_page_view_selectable_my-cms-page_CustomJs.xml
<?xml version="1.0"?>
<page xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/page_configuration.xsd">
<head>
<link src="js/custom.js"/>
</head>
</page>
I've run cache:clean
and cache:flush
multiple times, index:reindex
ed, and run setup:upgrade
until my eyes bled. This site does have multiple themes/sites so maybe there's something there I need to do? Any idea what I'm doing wrong?