MySQL GTID error 1236
You need to take dump from Master to replicate.


  master has purged binary logs containing GTIDs that the slave
  requires.


Master delete its binary logs and create a new binary logs file. That's the reason when you implementing replication after taking dump is working because it's getting gtid_executed and gtid_purged that is available in the current binary log.

But when you are implementing without dump, The gtid_executed and gtid_purged getting matched because Mater already purged it.

So you must have to take dump and even sometimes you need to set the gtid_purged manually on slave.

You can read this, it has explained very well.
https://www.percona.com/blog/2013/02/08/how-to-createrestore-a-slave-using-gtid-replication-in-mysql-5-6/