Joomla has had support for Web Authentication for
some time now and this has worked well since its inclusion. That
was until the server of the Fido alliance was no longer reachable
due to an outage.
This resulted in Joomla sites trying to contact the Fido alliance
server but receiving no response, since the response was taking
some time users noticed that their sites were getting slow.
As more sites were trying to reach the Fido server it became even more difficult to contact the server, causing even more disruptions.
This was a very difficult bug to test for as it relied on a third-party server experiencing problems hence it did not come to light while testing 4.2.1
The Joomla 4.2.2 release comes with the Fido token so we no longer have to contact the Fido server every time we need an updated token. This will improve the load times for your site....
Read more https://www.joomla.org/announcements/release-news/5867-joomla-4-2-2-bug-fix-release.html