The situation: you answer a question/OP mentions it works, but.../does not accept, does not upvote the answer, never comes back.
Then there is the exact same question, cannot be marked as a dupe, so you leave a comment, pointing to the unaccepted (but working) answer of the first question. However, OP has reputation 3, and cannot upvote, both questions stay seemingly "unanswered".
Is it acceptable to (re) answer the question on the second instance, so at least one of them gets accepted, and the oldest one can be marked as a dupe to the newest? (and no third version of the same question will possibly appear)?
These are the questions in my example: