Hi Savita,
The following things need to be checked:
1) Is the fixed cost created from a past date? In Fixed Cost creation wizard, while specifying cost details, 'Update for the effective period' and a From date needs to be selected.
2) While configuring the fixed cost on the entity, please check if the correct cost model is selected, which is being used for report generation.
3) While configuring the fixed cost on the entity, please check if the 'Update from the effective period' option is selected with a From date.
4) Once a Fixed cost is added to the list, make sure to press the 'Update Fixed Cost' button.
Hope this helps.
Thanks,
Piyush