I put close... not on topic... belongs on other site. The only "other site" listed was meta.english. I would expect either a list of all sites or a freeform text field.
This is not a bug. This is "by design" so that users can't just send questions here and there with nary a care.
For example, we used to be able to migrate from EL&U to Writers. However, that caused problems because many EL&U users don't actually know what goes on at Writers, so bad migrations happened and that path was closed to us.
Paths for migration by us normal users must be opened by the Stack Exchange team. This doesn't happen very often.
If you want to recommend that a question be migrated to a site not in the currently approved list you can flag it with "other (needs ♦ moderator attention)" and specify where and why.