According to its timeline the last activity was mine (I posted an answer). However, I answered it on Stack Overflow before its migration here. Maybe it is the cause of this display bug?
Edit: this was erroneously closed by a mod as a duplicate of this question, however as it becomes clear after reading the Jarrod's answer it is not:
- Jarrod Dixon ♦ posted that the other issue was caused by the fact that "at the time of migration, the question owner did not exist on SU". This is obviously not the case here since I've had an account on SO and MSO for over half a year.
- The issue is
status-completed
and Jarrod Dixon ♦ said that the field will be updated if the user registers an account on the website the question was migrated to; but again, this is a whole different bug.