@dimalifragis Thank you very much, the issue was that plugin JQuery Updater was currupted. I reinstalled it and wpForo began to work normally.

OSL support discovered the problem. It is Akismet integrated with wpForo. It puts his hidden input to the place of source code where social buttons sh...

No exteranal cache for any WP Foro pages. Thanks, I'll write to OSL support.

@robert, Yes, I have test.* version of my site. I disabled all plugins except wpForo and Query Monitor - the problem remained. Still slow "wpForo"...

As for lookback issue, I don't now how actually locate it. I've installed Site Heath plugin, it reports: Your site couldn't complete loopback requ...

@robert The URL of the page is DB is MySQL 5.7.22 (InnoDB is on) The report of Query Monitor regarding functions of this slow queries: WP_Que...

Screen #2 - part of slow queries list q_wpforo2.png Screen #3 - wpForo deactivated. The page generates during just 1,58 seconds (red strip on top...

@robert, thank you!

@alvina, thanks for discovering the problem. I've fixed it by adding "width: 730px" to "#wpforo #wpforo-wrap .wpforo-post .wpforo-post-content" in sty...