I am getting below heatmap for the above data window where there is no event but the heatmap value is close to 15.

When there is an event in the data window the heatmap threshold is 15 which is same as the above threshold when there is no event in the data window

Any suggestions in generating the heatmap graph?
I am getting below heatmap for the above data window where there is no event but the heatmap value is close to 15.
When there is an event in the data window the heatmap threshold is 15 which is same as the above threshold when there is no event in the data window
Any suggestions in generating the heatmap graph?