[N1QL] merge query throws an error that it didnt use to

There are two buckets with primary indexes on both buckets, backup data will be attached. 2 nodes in the cluster with data query and index services. Buckets names are default and standard_bucket0.

This query:

MERGE INTO default USING standard_bucket0 s0 on key "merge_delete_wherequery-testemployee13436.4244112-0" when matched then delete where s0.name LIKE "employee"

Returns this:

[
{
"code": 5320,
"msg": "Multiple UPDATE/DELETE of the same document (document key 'merge_delete_wherequery-testemployee13436.4244112-0') in a MERGE statement"
}
]