Jira Service desk customer permissions - not saving

[John Smith]

Hi All,

I'm trying to set my Jira Service Desk > Configuration > Customer Permissions so that customers can create their own accounts. I can select the appropriate radio button option but there's no way to save it. And if I navigate away from the page and back again, its not saved. I'm signed in with Jira administrator privileges.

Why can't I save this option?

Thanks

(See screenshot below)