iThemes Security move WordPress URL

Hi, I used the ithèmes security option to move the URL of my WordPress, I received by email the confirmation of my new URL, but now I can access my WordPress either by my old URL or by the new one. I tested on another PC, it’s identical. I went back and put the old URL back and now it works as before old URL OK and the one I wanted in new Not Found. Do you have a solution? or tell me where the problem lies. Thanks in advance.