Is there any way to update DOH settings (e.g. NEDNSSettingsManager.dnsSettings.serverURL) after the extension was enabled? Currently, saveToPreferences doesn't reload current settings and they will be reloaded only if you will enable/disable extension in the settings. Maybe it is a bug and will be fixed in the future betas?
Reload DOH settings
This is a known issue, and should be fixed in the next beta of iOS 14. Thanks for reporting!