Your problem may be related to old cached settings.
Please try to clear your browser history before you trying to open the AVD settings page. Either please try to refresh it so the content to appear.
Related article named "Mozilla policy restrictions" available at our Knowledge Base FAQ: https://support.ant.com/kb/en-us/4-faq/50-mozilla-policy-restrictions
Please note that you can provide more details about your problem without any registration to our support here: https://www.ant.com/support_form