It used to work before I updated the website to Joomla 4. Now it shows content for half a second only. Any ideas why is it so?
Example is here: http://host1853202.hostland.pro/?view=article&id=2278:ruhi-5&catid=113:main_sequence (in the middle of the page)
On the attached screenshot I show how it looks on Joomla 3 website.
Is that custom collapse you added into article or from our demo site?
as it seems that collapse doesn't work in Joomla 4 any more, you can check the same with default Joomla template.
It was a custom collapse. OK, I’ll change it into something else then.