Calculate result as average in the report not showing average for all

Hello,

I have a calculated key figure in the query where its result should show average. I have made a setting for this calculated key figure as:

1. Calculations tab: Calculate result as "average" and calculate single value as "nothing defined"

2. Aggreagation tab: exception aggregation: Total and reference char: []

Now coming to report, BEX it showing correct average for all cells but when i run it in portal few values it is showing correct average but for few it is showing as blank. I exported this to excel then cell shows blank but cell has some values in the custom format and display values when i change the format to general from "format cells" option.

Please help me in resolving the issue- why portal not showing value for all.

Thanks,

Vijaya