When I go to “Settings: New Goal Defaults” and make a change, and press “Update” or “Reminder Settings” in Firefox, I get the message
This page is asking you to confirm that you want to leave - data you have entered may not be saved.
You have to press “Leave Page” in order to get the update to work, even though you’re not actually leaving the page.
This confused me a few times and I had difficulty changing the settings.