Running ultimate_cron by system cron currently requires drush. Using drupal console cron call does not work as drupal console reinvented the wheel by writing their own cron call implementation (more or less copy pasting the actual core CronInterface logic).
Add drupal console command to call ultimate cron directly (actually adding a command which calls the defined CronInterface).
Closed: won't fix
2.0
Code
Not all content is available!
It's likely this issue predates Contrib.social: some issue and comment data are missing.
Correct me if I'm wrong, but I think drupal console is pretty unmaintained now and everyone switched back to drush? Therefore not going to add that to the project as something that would need be maintained and updated.