This incident has been resolved. Our apologies for any inconvenience caused.
Update · UTC
The team has implemented a mitigation for all affected sessions over the past 48 hours. Book reports are now downloading as expected. The team is continuing to implement the mitigation while we investigate a fix.
Identified · UTC
Our team has been notified that book reports are intermittently failing to download. The team has identified the source of the problem and is actively applying mitigations to resolve it while investigating paths to a more permanent fix.