sysbench failed to initialize w/ MaxScale read/write splitter

When sysbench "run" executed on MaxScale host via readwritesplit port,

sysbench failed with following error :

sysbench 1.0.9 (using system LuaJIT 2.0.4)

Running the test with following options:
Number of threads: 1
Initializing random number generator from current time

Initializing worker threads...

FATAL: Worker threads failed to initialize within 30 seconds!

/var/og/maxscale/maxscale.log:

2018-02-07 17:50:36 error : (7) [readwritesplit] Failed to execute session command in [192.168.100.12]:3306. Error was: HY000 This command is not supported in the prepared statement protocol yet
2018-02-07 17:50:36 error : (7) [readwritesplit] Failed to execute session command in [192.168.100.11]:3306. Error was: HY000 This command is not supported in the prepared statement protocol yet

Query Log All Filter output:

Date,User@Host,Query
2018-02-07 17:50:36,maxuser@::ffff:127.0.0.1,SELECT c FROM sbtest1 WHERE id=?
2018-02-07 17:50:36,maxuser@::ffff:127.0.0.1,SELECT c FROM sbtest2 WHERE id=?
2018-02-07 17:50:36,maxuser@::ffff:127.0.0.1,BEGIN
2018-02-07 17:50:36,maxuser@::ffff:127.0.0.1,COMMIT

MaxScale 2.1.13 worked with sysbench 1.0.9 w/o 2.2 specific automatic failover settings.