PHP version 7.3.6 , Joomla Version 3.9.5, Virtuemart Version 3.2.15
Base Template Gantry5 - Helium

even though I turned off the option "Use jQuery chosen for dropdowns in FE", i still getting double dropdown boxes (www.climabox.gr/climanew/images/errors/Screenshot_1.jpg)

how can i rename tabs in product details. i created language files everywhere i found flexible in english but it doesn't change! (www.climabox.gr/climanew/images/errors/Screenshot_2.jpg)

when i select a shipping method i get an error (www.climabox.gr/climanew/images/errors/Screenshot_3.jpg)

Thank you in advance!