Hi @Raumen837,
To correct the current issue, you can run:
/opt/kaltura/bin/kaltura-sphinx-reindex.sh
To make sure it does not happen again, ensure /etc/init.d/kaltura-populate is running on both Sphinx instances.
If it is not, then that would explain it.
You should see this process running on both instances:
/usr/bin/php populateFromLog.php
This logs to /opt/kaltura/log/kaltura_populate.log