I've noticed this before, but I didn't have enough data to tell if this is a repro, or if it was a one-off error.
Yesterday, two questions (audio ads and jQuery CDN) were migrated here to MSE from MSO. When I went to check in on both of them, my vote was gone, but the score hadn't changed. As in, my vote was preserved, but I can still vote again. It's not associated with my account I guess.
This happened once on an SO migration to MSO - score and vote count remained intact, but I could vote again on the post. Considering child metas have the same UIDs as its attached main site, this isn't a UID issue (so someone who happens to have my SO UID here on MSE doesn't get ownership of my votes on the migrated posts).
Also, if I do vote on the posts, the score does change. There's no update and re-association of votes going on behind the scenes. My second vote acts like a completely separate vote from a different user, not a caching bug.
In case it wasn't clear, steps to reproduce:
- Vote on a post
- Vote again
Note that this also applies to answers affected by the migration - not just the question
I'm assuming this is a bug, but what's going on here? Why not associate votes with the global account ID to prevent users from voting twice?