The cash flows linked to the sources and uses are recorded by the software in the opening balance sheet in order to isolate the impact of exceptional elements linked to the creation of the company, and thus to make the financial statements comparable throughout the business plan.
If you prefer to see them appear in period 1, simply change the mapping of your elements from the "start of plan" date to the first month of your forecast. However, if you do this, you will not be able to use the sources and uses table.