Secondary/Additional service cannot be booked

Hello,

1. I have installed latest version of your plugin on https://www.vintagebarber.sk and here is rezervation/booking page: https://www.vintagebarber.sk/objednat-sa/ and if i enable secondary Service then user can not book any service, i get this notice: Not enough time for this service, or please see screenshot:

The page I need help with: [log in to see the link]