Resetting autotag prompt

Hi, working in Acrobat Pro DC (2015 Release - Classic) and having an issue with the Autotag Document tool. Typically when using this tool on a document that has existing tags, there's a dialog box saying (paraphrasing): "This document is already tagged. Retag?" with Yes/No buttons and a checkbox to save the response as default.

However, if you select No and the checkbox to save that setting, the Autotag Document tool will now do absolutely nothing (no dialog box, no tagging) when working in a document that's already tagged. At this point, the only way to use the tool, as far as I can tell, is go into the Tags panel and manually delete all tags, and then use the tool; it'll tag the document, but you won't get the prompt at that point either, since there weren't any existing tags at that point.

Haven't had any luck in searching for a way to remove the selected default and restore this prompt -- any help would be appreciated. Thanks!