$__interval always set to 5m

I am running Grafana v4.4.1 with influxdb. I have created a graph with the following query:

select mean("sum") from (SELECT sum("count") as sum FROM "pg_connections" WHERE $timeFilter GROUP BY time(1m), "application_name" fill(null)) GROUP BY time($__interval), "application_name";

For some reason the $__interval always returns 5m whether I look at 3 years worth of data or 1 hour.

I try to understand to make this variable dynamic.

Can someone give me a hand ?