I have asked a question today and one member was voted as duplicate and private feedback was there, I choose no and submitted the form. When I revisit the question or refresh the page same notice reappears with yes/no options.
In-network tab I got 200 OK status and response as "success":true
OS: Windows 10
Browser: Chrome 79.0.3945.117 (Official Build) (64-bit)
There was a bug with this component where it only worked part of the time. It should now work in all cases. I have also added functionality to it to delete the "is this a duplicate" comment that is associated with the rejected flag(s).