Parent issues no longer diplay?

I see the parent issue on #2229149: Add Drupal Issue Metadata for Twitter Cards. Which issues is it missing from?

Somehow this got into a state where the reference wasn’t saved in the field_data_field_issue_parent table, but was present in the field cache. So it was showing on the edit form, but Views queries didn’t see the reference. Updating the issue got everything into place.

The commit comment was posted the same second as your comment adding the reference, so the field cache and/or each process’s static cache must have hit some sort of race condition.

I haven’t heard any other reports of behavior like this lately, so I’m going to be bold and call this fixed.