I initially flagged this question as a duplicate of another question, but then realized the other question was not exactly a duplicate. I then found a better (exact) duplicate, and tried to correct the original flag.
The system did not allow me to flag as a duplicate again, as the original question was already flagged as a duplicate. So I unflagged the question, so far so good. I was then thinking it would allow me to reflag the question as a duplicate again. But somehow it does not, saying "you have retracted your recommended closure flag".
I eventually deleted the automatically added flagging comment and manually added a comment mentioning the better duplicate.
Is there a way to adjust a mistaken duplicate flag?