In MariaDB rocksDB engine, insert statements are failing when binlog format is MIXED

Question

MariaDB [rockdbeng]> insert into test values(1),(2),(3);
ERROR 1105 (HY000): Can't execute updates on master with binlog_format != ROW.
 

I was getting the above error. When I changed the binlog format to ROW insert went fine. Why did I get that error?