This is still an issue with WP 6.7+. ACF blocks that have WYSIWYG fields within them will throw a JS error if the initial view state for that block is Edit mode. Setting SCRIPT_DEBUG to false fixes the issue.
I’ve done a bit of debugging and it looks like the textarea field IDs for the WYSIWYG fields do not update on page load with SCRIPT_DEBUG enabled. The field IDs are still set to something like “acf-editor-677c024e3e39b” instead of “acf-editor-179”. Disabling SCRIPT_DEBUG or swapping between the Preview and Edit modes will fix the broken field.
