Authentication fail on Ubuntu 14.04

Using readwritesplit - the following error happens:

1. mysql -h172.18.1.45 -P3309 -p******* -u*******
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   Your MariaDB connection id is 10748
   Server version: 5.5.42-MariaDB

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MariaDB [an]> select * from *******;
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id: 10748

Looking at debug log:

2015-10-11 21:42:55 140689459013504 [gw_read_backend_event] Read dcb 0x337eae0 fd 20 protocol state 4, MYSQL_AUTH_RECV.
2015-10-11 21:42:55 140689459013504 [dcb_read] Read 75 bytes from dcb 0x337eae0 in state DCB_STATE_POLLING fd 20.
2015-10-11 21:42:55 140689459013504 [gw_receive_backend_auth] Invalid authentication message from backend dcb 0x337eae0 fd 20, ptr[4] = 0xff, error 28000, msg Access denied for user '*******'@'172.18.1.45' (using password: NO).
2015-10-11 21:42:55 140689459013504 [gw_read_backend_event] after gw_receive_backend_authentication fd 20, state = MYSQL_AUTH_FAILED.
2015-10-11 21:42:55 140688884750080 [poll_waitevents] epoll_wait found 1 fds

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Password seem to be dropped from MaxScale connection. I've checked for underscores in grant table... but there are none - and same config works when running Maxscale 1.2.1 on a 12.04 server.