Meeting registration fields disappear after saving

I am setting up a meeting which requires registration. I have selected job title and organisation as additional required fields to the default and clicked Save All. I can see they are ticked.

When I navigate away to the Details tab and copy the URL for the meeting into my browser, those additional fields aren't there. And when I go back and check, they are now not ticked any more.

Have tried this multiple times, cancelled the meeting and set up a brand new one... and just cannot get the fields to stay saved as required and therefore appear on the registration form.