When I am at platform subtab, there are no data being sent for graphs. Server sends out empty buckets, but no data inside them

{
"start":1448248168095,
"end":1448248888095,
"min":"NaN",
"avg":"NaN",
"median":"NaN",
"max":"NaN",
"samples":0,
"empty":true
}

However with enabled debug mode, data seems to be collected (Metric collected: Procesor_Name->[0.044600])

Is there a problem with wrong xml settings or somewhere else?