Hi there! How familiar are you with browser’s developer tools? The reason I ask is that I think that perhaps there is a javascript error that’s causing the autocomplete functionality to not work. If you can use your browser’s developer tools console panel, you might be able to see if there’s a javascript error message which can help us pinpoint where exactly the issue is coming from. See https://en.wikipedia.org/wiki/Web_development_tools#Web_developer_tools_support for more information about browser developer tools.
Another thing you can try is to re-run the WordPress update. Sometimes files don’t get updated like they’re supposed to and re-running the update just might fix things.
And if all else fails, you can revert to a backup until you figure out where the issue is and how to fix it.
That is indeed a javascript error! Unfortunately I can’t tell what might be triggering it – but it does provide a clue – something is making a call to mootools.js (a javascript framework that is not in core WordPress – so it’s likely from a theme or plugin) and something in that process is breaking.
So now you’ll need to track down what exactly is doing that. I would try out this plugin: https://ww.wp.xz.cn/plugins/health-check/. It has a handy feature for disabling plugins and themes but only for your user account – end users to the site will still get your awesome site with all it’s plugins and its selected theme. This way you can troubleshoot your site and identify where the issue is coming from without impacting visitors. Once you’ve identified the issue you can contact the theme or plugin developer for further support.
I hope this helps!
