It looks to be some sort of conflict with the swipebox plugin. Clicking any link triggers the swipebox modal (where I believe normally it should only do so on media-based links – images, videos, etc.)
Maybe look to see if that plugin requires an update or disable it temporarily to see if that is indeed the culprit.
There have been other reports of problems with swipebox. Make sure your plugins and themes are up-to-date. Also, try this: Please try installing https://wordpress.org/plugins/enable-jquery-migrate-helper/ to see if that fixes the issue.
For more information on what this is all about, see https://wptavern.com/major-jquery-changes-on-the-way-for-wordpress-5-5-and-beyond
If the plugin helps, please contact the developers of the plugins or themes noted in its admin messages.
Thanks for the replies. Unfortunately I am not running the swipebox plugin and everything else has been updated. I have installed and activated the jquery migrate helper plugin and rebooted but that has not solved the problem.
All the themes are up to date, but I note that the site is running a child theme based on Genesis, which was created by the website developer. Though Genesis itself is up to date, is there any chance this is the source of the problem and do I need to change the theme?
This may be a plugin or theme conflict. Please attempt to disable all plugins, and use one of the default (Twenty*) themes. If the problem goes away, enable them one by one to identify the source of your troubles.
If you can install plugins, install “Health Check”: https://wordpress.org/plugins/health-check/ On the troubleshooting tab, you can click the button to disable all plugins and change the theme for JUST you, while you’re still logged in, without affecting normal visitors to your site. You can then use its admin bar menu to turn on/off plugins and themes one at a time. See https://make.wordpress.org/support/handbook/appendix/troubleshooting-using-the-health-check/ or https://rankmath.com/kb/check-plugin-conflicts/ for more information.
Further to my last post. The jquery migrate plugin did work, after all. I chose settings and rolled back to the legacy jquery. I realise this is not a permanent solution and thank you for all your help!
