Hello, I migrated k2 content to joomla articles and upgraded to joomla 4 and everything was fine on my test site, but the migrated articles are giving a 404 error once I published the website. Any hint?

Here is the working page on the test site:
https://testsite.formalms.org/forma-plugins/375-2factor-authentication-plugin.html

Here the production site:
https://formalms.org/forma-plugins/375-2factor-authentication-plugin.html

Can deny registration if there is spaces in the username?

Does this module support multiple languages or is it limited to English?

Is it possible to apply restrictions to specific user groups?

Is there a limit to the number of iframes I can insert in one article?