I can confirm it is Yoast SEO that is causing the issue.
@kuckovic the theme version is the latest 3.4 and we do not use generate blocks, we use Elementor
Thanks @kuckovic I was hoping someone would rule the theme out (without me re-installing twenty theme)
No errors in console no.
I have seen someone else with the same issue on Stack Overflow (2 days ago) but no answer yet other than core roll back.
https://stackoverflow.com/questions/78777508/editor-view-broken-after-updating-to-wordpress-6-6
The only plugin I can see being used above that we use is Yoast.
