Max aggregation strange behavior in Topbeats dashboard

Hello everybody.

I'm testing the Beats dashboards in Kibana and I'm getting a strange behavior with the topbeat's cpu usage graph because always returns zero value.

I've created a new visualization with the same metrics using the max aggregation and I get the same results. I don't get why , because the records have non zero value all the time. Could you help me understanding what's going on?

Example:

"cpu": {
"user": 405432,
"user_p": 0.0405,
"nice": 1117,
"system": 244784,
"system_p": 0.0264,
"idle": 10914762,
"iowait": 82614,
"irq": 0,
"softirq": 453,
"steal": 0
},

Thanks in advance,

Ignacio.