Hardening cannot be applied on multisite

Plugin version 2.1, WP version 6.8.1, PHP version 8.2.28

I installed Sucuri on several websites, including a few multisites. On the non-multisite websites the hardening was successful, however, when I try to apply it on the multisite I am redirected with message “Unfortunately, you are not authorised to access this page.”. I am logged in as the network admin.
There are no errors logged to debug.log.

Is this a known issue for multisites, or is there a way I can access more information about why this could be blocked?