Metric value doesn't show consistantly as 1 from mongodb_exporter

Greetings
Hopefully I am not missing something obvious but have been cracking at this with a couple of colleagues. We’re hitting a sight problem with being able to see the balancer metrics in percona’s mongodb_exporter. Love the detailed metrics just can’t get this one rocking.

Grafana promQL:max(mongodb_mongos_sharding_balancer_enabled{cluster=“$cluster”})

mongodb_mongos_sharding_balancer_enabled

(cluster values are valid in the template) tried without max as well.

Can’t get the mongodb_mongos_sharding_balancer_enabled value to show as 1 (in PromQL or Grafana) or True although the balancer is always enabled. I see it showing as 1 occasionally but as I understand it should always be enabled and have a value of 1 or True. max(mongodb_mongos_sharding_balancer_enabled{cluster=“$cluster”})

The dashboard and value should always be 1. We’re lookin at doing monitoring so the promql and accurate result would be key to be sure the alerts are ok.

Our env
RHEL 7.2
Prometheus 2.0
Percona mongodb_exporter
mongodb_exporter, version 0.3.2 (branch: master, revision: adabd4fdd9b9a8835c2e57c327aa8d2dee9650be)
build user: xxx_xxxxxx
build date: 20171121-15:49:23
go version: go1.8.3

Here is a Grafana screenshot if that helps.