A simple alter crashed complete cluster after changing ENUM with mariadb internal code: 1677

ALTER TABLE `table_name`
CHANGE COLUMN `column_name_9` `column_name_9` ENUM('1','2','3','4') NULL DEFAULT NULL COLLATE 'utf8_general_ci' AFTER `column_name_8`;

All 5 nodes exited with:
2018-09-26 8:40:42 87095127 [ERROR] Slave SQL: Column 7 of table 'xxx.table_name' cannot be converted from type 'enum' to type 'varchar(300)', Internal MariaDB error code: 1677

Table schema:
column_name_1 int(1) unsigned
column_name_2 int(1) unsigned
column_name_3 datetime
column_name_4 int(1) unsigned
column_name_5 smallint(1) unsigned
column_name_6 int(1) unsigned
column_name_7 int(1) unsigned
column_name_8 varchar(300)
column_name_9 enum('1','2','3')

So server can't change column 7 from type of column 8 to type of column 9 ?

Why would server issue a change on wrong column?

This happened on both TOI and RSU, while on RSU just the local node crashed, on TOI this happened to all nodes.

We were checking if slave_type_conversations could fix the issue, but this can't fix the problem of changing the type of a wrong column?

https://mariadb.com/kb/en/library/replication-and-binary-log-server-system-variables/#slave_type_conversions

Hopefully we can resolve this quickly, since this never happened on 10.1.x versions.

Thanks!