Hi,
Is your benefit plan a Monthly or Yearly??
if its an annual benefit plan but the TSV is monthly then you can see behaviour like above.
Can you check if you are hitting something like the below STR. If so then its a potential bug I had created pending development review..
STEPS TO REPRODUCE
1. Navigate to Financial plan - Cost Plan of any financially enabled project
2. Create a new manual plan with
Period Type : Annual
Start: 2016
Finish: 2018
Grouping Attributes: Any grouping attributes is good
3. Save
4. In the Detail tab, click ADD
5. Create a line item for the grouping attributes
6. In the details tab, click configure - TSV
7. Start Date: Specific Date - 1/1/2016
Time Scale: Specific Time Scale - Month
Number of Time Periods: 12
8. In the TSV, for 2016-01, enter 12000 in the planned cost
Expected Results: 12000 stays as it is in the 2016-01 grid
Actual Results: The 12000 gets spread across all the months of the FY.
Thanks,
Jerin