WordPress Dashboard add user password not working, etc

In order to investigate the problem, follow these steps:

  1. Make sure everything is up to date. Including WordPress itself, active theme and all of the active plugins.
  2. Check browser console (Hit F12 in Google Chrome). If there is any red error message regarding javascript, it can make the page unresponsive like clicks are not working.
    In the error message, the source of the error is visible, you can see which file, from which plugin or theme is causing this issue, deactivate it and see if it resolves the issue or not.
  3. Install and activate jQuery Migrate plugin if you are using the latest version of WordPress and some old plugins that are not updated after WordPress 5.5.
  4. Enable debug mode and check the debug log to see if there is any PHP error in your WordPress installation. If there is any, try to resolve it.