In Build 17713 the Feedback Hub doesn't work. It's just a dead link.
Also something more annoying is that the Windows notification popups are delayed - they don't come in as they happen, but they all come in at once at various times. For example, if I get an email at noon, 1pm and 2pm - no notifications from Outlook will appear as they come in, but maybe at 3pm all the notifications for noon, 1pm, and 2pm will come in together. Hoping this is fixed in a future build soon as it is quite annoying.