How do I turn off MariaDB GTID to revert back to binlog replication?
On each slave, run this. It'll do it without downtime and very little replication delay.

stop slave; change master to master_use_gtid=no; start slave;


You can watch show slave status \G, specifically "Using_Gtid, "Master_Log_File" and "Read_Master_Log_Pos". Assure the first is "No" and the other two are climbing after this command.