The Blog Search APIs only delivered approximately 3/4th of the data indexed between 2017-12-04 10:04 CET to 2017-12-05 12:10 CET for a majority of the queries during the same time period. The problem was due to a machine in the cluster silently ignoring index requests. We will improve on our monitoring to ensure that this will not happen again.
We advice you to re-run your search queries if you believe this affected you. We are sorry for any inconvenience caused.