N1QL Queries not Load Balancing between Query Nodes

Problem

I am seeing N1QL queries not load balancing between available query nodes. This causes excessive CPU on the heavy hit node.

Description

Using a 4 node 4.5.0 vagrant cluster, 2 nodes are Data only, and 2 nodes (103 and 104) are Query/Index nodes. When issuing a simple N1QL query in a loop, one node receives more than twice the query load. Sample code and screenshot attached.

I used the beer-sample bucket, and deleted the primary index. I created a covering index:

create index name_idx on `beer-sample`(name);

ASK

Please determine why the query requests are not more evenly distributed