In March 2015, a change was made to the close voting system, to allow users to recast close votes and close flags 14 days after they age away.
However, according to this post, apparently votes that were cast before the change was made cannot be recast. The user in question was trying to recast a vote in 2016, but was prevented because they cast a now-aged vote back in 2011.
Why is this the case? Is this intentional, or is it a bug?