Folks,

Below is what the customer is executing:

DROP TEMPORARY TABLE IF EXISTS ygcjdfiorq_rpb; 

 CREATE TEMPORARY TABLE ygcjdfiorq_rpb([...snip...]); 

 LOAD DATA INFILE '/tmp/ygcjdfiorq_rpb.csv' INTO TABLE ygcjdfiorq_rpb FIELDS TERMINATED BY ',' OPTIONALLY ENCLOSED BY '\"' LINES TERMINATED BY '\n';

Right after that data load, a SELECT query is sent and even having MaxScale logging that "Multi-statement query or stored procedure call, routing all future queries to master.", right after data load reading, part of the same session/thread is sent to a slave, where the TEMPORARY TABLE can't be read and then, application throw an error.