Shipping settings not working

Updated to the latest version of WC this afternoon, and now we cannot change any of our shipping methods or zones. They are still working as intended on the front end but are not listed in the settings pages, nor can we add any new ones. Clicking on ‘add shipping method’ just reloads the page, and ‘add shipping class’ does nothing.
nb : no classes or methods are shown on the settings page but they are visible when checking out and work as expected, so they are obviously still in the database, just not being picked up in the admin pages