Financial Plan Spreadsheet Periods

I have the financial plan enabled to be time phased by GL period. The spreadsheet downloads and allows entering budget amounts for each period. However, after uploading, the budgets are showing as a single amount, rather than spread across each period. How do I get the budget amounts entered in each period of the spreadsheet to be reflected in each month of the financial plan?

Also, in the spreadsheet, the first period is several months prior to the period containing the project start date. I would expect that the first period available for budget entry would be the period with the project start date.