You can manually find and link payments to invoices.
Click the drawdown or fee-transaction on Transactions-page to see details.
Click Status-icon next of the investor's transaction.
Click Manage Transactions-button.
You will see payments made to fund's bank account which are not yet linked to any invoice.
Click the payment to link it to the invoice.
Click the linked payment to unlink it from the invoice.
Finally, create Update Transaction-button at the bottom of the dialog.