Node.js SDK v3.2.4 not load balancing among query services

Same issue as here: Java SDK 2.3.1 not load balancing among query services?

We have a cluster with 7 nodes, each node has the query service, but most of the query requests are forwarded to the same node causing that node’s CPU usage to be 99%. The other nodes have a CPU usage under 40%, some even below 10%.
On the sdk side we are facing a lots of “TimeoutError”.

If we restart the sdk connection to the cluster we can see that the queries are correctly balanced among the cluster nodes, bust after 20-30 seconds all the queries are forwarded to the same node causing a lots of timeouts

FYI: seems like a sort of caching problem at machine level.
Restarting the node.js process via pm2 did not solved the issue. Rebooting the entire server solved the issue.