Bar graph is missing terms for split chart

Hi

Please help me with this specific issue as this is critical.
ELK 7.2
I am getting access logs data from both Apache and IIS logs and storing in filebeat-index.

I am trying to create a bar graph to show number of hits made to our environments.

I have divided servers in to a groups using fields.env: field.

When I create a bar graph and filter it per every environment the data shown on Graph is not accurate and missing some values.

For example.

I see an empty bargraph for 1 hour time for environment called "10.8"

At the same time when I look at discover tab I see different results. I see count as 20.

I see similar discrepencies in the graph. Please tell me how I can properly configure this.

Below is my configuration.

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Here is one more example.

I am trying find number of users accessing a url in last 24 hours. I see one documents

But the bar graph does not show any data.
If you notice the top two show the user and urls accessed as "1", but the bar graph is empty.

Now if I change the bar graph X-axis histogram settings. Its showing different result. So is the graph not counting the documents or agent.hostname number. Why the result has changed to a decimal number?

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