A long-standing data loss bug with --bypass-gc was reported today in https://tracker.ceph.com/issues/73348. If any of the deleted objects had been copied to/from other buckets, --bypass-gc deletes the data of those copies too. As a result, the copies are still visible to ListObjects requests but GetObject requests fail with NoSuchKey. You can follow https://tracker.ceph.com/issues/73348 to track the fix and its backports. In the meantime, use 'radosgw-admin bucket rm' without --bypass-gc which correctly handles copied objects.