Hi your before after extension is having issues with Joomla 4 backend article interface is conflicted with Joomla 3 buttons and dropdowns when editing articles. Button - JUX Before After Site Plugin 1.0.3 December 2018 JoomlaUX editors-xtd No 10104
Thank you for your feedback.
We have checked our extension on Joomla 4 with article editor. Yes, it have some conflict with article editor. We will check it and release a new version to fix that issue soon.
Please wait for us.