Need help with DAX Query DISTINCT Count

Hi all,

I have a table where I am using a measure to find the count of distinct Rkey's in a table that has the level > 5.

The DAX statement I am using is giving me wrong data. 

Measure 1 := CALCULATE(COUNTROWS(DISTINCT('Event'[RKey])), FILTER('Event', 'Event'[level] > 5))

When I use this for a query I am getting wrong data. I am seeing data for Keys that doesn't have any event on that particular day. 

Please help me in understanding what I am doing wrong.

Thanks in advance.