Hello,
You can go in the vendor account details, under "Statistics" and see the list of its sales and the invoices you created for its payments.
When you click on the "pay" button after selecting some vendor orders, you confirmed the payment of these orders ; so that's normal that the orders are not longer seen as "unpaid".
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.