I replaced the local database with the latest one to be sure I had no leftover blocks experimenting with all. Still I see
TypeError: null is not an object (evaluating 'e.addEventListener')
Global Code — toggle.js:7
Selected Element
<div class="block-editor-block-list__layout is-root-container" data-is-drop-zone="true" data-select2-id="3">…</div>
so perhaps it is caused by another block. Annoying though as it kills display of my new block in the editor. Seems to be related to a WordPress default block as the class is called block-editor-block-list__layout. Will try to see what it is.
Checking console in Firefox Developer I now see
Uncaught TypeError: can't access property "addEventListener", e is null
<anonymous> https://site.test/wp-content/themes/theme/blocks/pricing-toggle/toggle.js?ver=5.8.1:7
So will see if that block error is causing my block not to display well in the editor.
