Userlist search and pagination not working

Many thanks for this reply.
I'll try the tests you wrote. I'll inform you if I find something

FYI, the pagination works with this workaround : right-click on a number of page, open in a new tab, the second page of the list displays properly...
Does this ring a bell ?

The paging is just a standard URL with the next page specified as a URL parameter. Opening in a new window will just navigate to that URL. While clicking it will submit the userlist search form to ensure search criteria goes to the next page as well. It'd be the form submit behavior causing you issues in this case.

Checking your site when you click the pagination it's throwing "Enter the username and password.". So for some reason it's trying to POST to CBs login form. It maybe due to some broken HTML caused by your popup login module. Disable the login via the CONNEXION button and see if that solves it.