I posted a question and then realized it was being associated with a second user account I had apparently created accidentally at some point. My reputation points are associated with the other account, so I deleted the initial question and then attempted to repost after logging in the correct user account. It's telling me the question is a duplicate, even though the original one was definitely tagged to be deleted. Maybe there's a delay before that conflict is automatically resolved?
This is something that the Stack Exchange employees need to take care of. Moderators can't merge accounts or reassign questions.
Use the contact form at the bottom of the page, and choose I need to merge user profiles as the option.
Set the profile link to the one for your primary account.
Then explain the situation.