During initial transfer everything is deleted on PLC side and transfer new (IP address settings as well). So make sure that IP address set in your project is the same one you are connected to. Otherwise you have to cancel transfer after reboot and set connection from Automation Studio new. Check this tutorial I made recently. https://community.br-automation.com/t/getting-started-with-b-r-hello-community-first-project-backend-plc-part/4676